Tuesday 21 May 2019 Peatland Ecosystems: Proxies for environmental change and current management. Anna Leveridge, Jordan Paker, George O'Ferrall of Soton Uni
Peatbogs are very wet , generally found in colder places. Not a lot
appears to be going on in terms of biodiversity but later on we'll
find it is important.
Peat is the layer of sediment that builds up , when organic matter
decays. It can be thick and so useful for re-constructing
past environments. There are 2 main types of peat bogs, blanket
bogs which look pretty homogenous when looked at from
afar. They hug the landscape and look like grassy hills etc.
Then reaised bogs that occur mor ein isolation , accumulations
of peat rising above the water table. So they are fed only by
precipitation rather than precipitation and gtound water.
Another one is the acrotelm which is the active peat layer at the
surface , where things get deposited and all the plant matter
decays. The sediment corer, a metal cylinder thrust in the
ground and can pull out a really long circular
core of the sediment.
The distribution of peatlands worldwide. Mainly found in Asia
and N America . Globally 4.2 milion sq km is peatland ,
which is about 3% of all land area. Europe has quite a lot especially
in Scandinavia. A significant difference between the peatlands
that build in the north of Europe and the south, because of patterns
of rainfrall and temp. They prefer colder temps and more
precipitation to build up. In the UK blanket bog forms the largest
semi-natural habitat. Important for bio-diversity and conservation,
because they are good at regulating C. They are eco-systms that
have high acidity and should be waterlogged if in good condition .
They are anoxyc which means no oxygen in there at depth.
This explains why peat accumalates rather than decomposes
unlike othere systems like forests. Without oxygen the plants canot respire .
Important habitat for lots of wildlife, species adapted to acidic
conditions. So endemic plants, ie plants only found in that kind
of ecosystem. A key species is spagnum moss , which produce
phenolic compounds which produce acidity , the main driver of the
conditions there. They are conserved under UK and EU law.
The Habitats and Wildlife Directives of EU law , transfered to
UK law on Brexit. Specialist species live here because of the
niche conditions. Not many species could cope with the low
pH and constant waterlogging. So GreenShank, Dunlin , Red Throated
Diver and Woodlark. And similar variety of invertebrates .
As these peatlands change potentially due to anthropogenic
forcing like extracting peat for peat-turf fuel , the ecosystem
changes and as it changes sometimes it becomes more like
heathland and changes the species variety supported.
So the benefits that humans can derrive from nature , 4 main types.
Culteral services, can't be easily defined in monetary terms.
Like taking a walk within nature and cnsequent well-being.
And the aesthetic value , wild and atural. Provisioning
services, that can more easily have a price tag attached.
eg fuel in Ireland 17C, animal bedding and as soil
conditioning for horticultural purposes. Regulating
services, benefits to water quality alone are worth 15 billion pounds
in the UK. So the way the environment reacts and responds to the
wider environment, such as sequestering C , mitigating
floods as peatland is essentially a sponge, protecting
downstream villages.
The historical archive that the sediment core can produce.
Using a combination of plant remains and pollen, its possible
to reconstruct pictures of past landscapes and past climates.
In the case of the UK peatland as far back as 10,000 years.
So why bother reconstructing past enviro. If you can reconstruct the
past vegetation of a site, then you can reconstruct its climate
and how the vegetation changes hsppen according to the climate
change. Of relevance now , because we can look back into the
sediment history and see how bio-diversity has responded
to potential climate change in the future.
Marine sediment cores and ice cores are used also, and for
much longer timescales . But on the local scale lots of benefits as being
more accessible and economic as no boat required and don't need to go
to Antartica. There isa large range f proxie measures. High temporal
resolution , so you can study many changes over a relatively short time
frame. Autochtonous, developed at site, not transferred from elsewhere or
redeposited. Maybe every 20 years rather than ice-core more like every 100,000
years. What can a tube of mud tell us, they contain , pollen , micro-fossils
and tephra. A proxy is something you can measure , and from that
measurement tell what something else is doing.
You can find traces of things like lead and titanium within cores,
and this can show human influences carried into the air. Traces of lead
can show the timing of the building of roads and the shift to unleaded petrol.
Titanium is a measure of erosion , can see when changes of land use
occured , just from measuring titanium.
Pollen under a microscope has different characteristics
for each species. They can be difficult to tell as not always nice
and flat, can be folded or torn. possible to create pollen diagrams, bottom
scale is percentage of what pollen species in the core . So birch, pine ,
alder ,beech, lime. Each species likes specific conditions. Godwin in
1940 saw this and that in some areas these patterns of
change are similar, he created a pollen-zoning system. Can be used to
compare with different areas, as C dating is expensive. Micro-fossils
are basically small pieces of plant matter , like seeds ,fruits ,stems .
These enhance the pollen record, as you can only see species that
produce pollen . There is good taxonomic precision , compared to
pollen which is generally limited to only family level , you could
say its Pine, not Scots Pine or another pine.
Different cores from different sites will have different depths.
Say in the New Forest , more organic deposits available, so
may get deeper faster than areas of ?? may be more shallower.
So how can we take cores from different regions around the world
and look at them in the same contexts. For that we use tephrochronology.
Tephra is volcanic ejecta , any ejecta, could be large boulders
, volcanic bombs, lakoli? smaller rocks and fragments. But here its
ash, tiny shards of minerals and rocks. Such ash gets pushed up
in the atmosphere , sometimes the stratosphere in large events.
Then its deposited around the world. This occurs on a rapid
timescale , in geological terms. This tephra deposit occurs in
about 1 year, so that one tephra deposition event in one
location will be the same time as any other location.
A thick layer would be alocal eruption If a very thin
layer of ash ,often hard to identify , appears as these shards
in otherwise organic. Each volcano has its own individual
fingerprint of spectrum of minerals. Find one mineral makeup in a
tephra location and the same or very similar mineral makeup in another location ,
they probably came from the same eruption.
So you can draw a line between them, although apearing at
different depths in the cores. Take the different depths and you can
create a model for age v depth per location. We can date the tephra
layers by likes of argon-argon dating but usually using mineral dating.
Tephra dating is the main technique for synchronising cores
from different locations, its not always plain sailing.
Tephra deposition is effectively synchronise in geoplogical
timing sense. Near volcanoes give deeper layers of tephra , but farther
away may get a thin layer or no layer. In extreme cases with cores
at the same site which don't have tephra layers in them
but move 10m away and have a different layer profile to it, less
shards . So we have to take multiple cores from
the same sites and average out what you see. You have to check that
cores that show no layers, from the same same site, are representing the
same time series. Also animal activity and plant growth within the
deposition area, so the often fragile ,thin tephra layers ,
especially in the northern hemisphere , where there is less volcanic
activity , can be disturbed . So faults can occur where material
slides down , so can appear younger or older simultaneously .
Also vertical mixing from tephra being deposited on top of a living
plant producing a more diffuse tephra layer. You want to identify the
paleosurface , the surface where you can say at this time , where we
dated this to , is the surface as far as internal composition.
The plant matter and the geological matter at that layer.
You cant say , this time period looked exactly like this,
just a geeral idea. With tephrachronology we can date volcanic
eruptions very specifically to each volcano. We also get apicture
of what disasters wer elike . I the last 10,000 years there has been a
lot of eruptions and disasters can define eras in geology, extinction
events define new eras of life on Earth. We come up with a very
real picture , that we can compare to today, to understand how
disasters happen. A core with thick deep tephra layers in a short
space of time , so many eruptions in one area could be hostile to life.
In recent history its possible to track very recent eruptions.
A study looking at tephra layers in Ireland , could track eruptions of a
singl;e volcano in Iceland over 1,000 years. For recent Icelandic
eruptions we'll be able to see those layers of ash in only 100 or 200 years .
So future geologists and geographers will be able to re-establish
our current environments.
Its possible to use volcanic eruptions to date eruptions on other planets,
not using peat cores of course. Coring on Mars would show ash
layers .
An important efect of peatland is carbon sequestration. Possible to us e
natural systems to take our C overload back out of the atmosphere.
Peatlands are possible the largest C store on the land of Earth.
Northern Hemispheric peat alone has 25% of the world soil carbon.
These peatlands can exchange 20 to 30 gram of C per m square, per year.
England alone has about 14,185 sq km of peatland, so many tons of
C has been sequestered in a year. A large ampount of C stored in these
peatlnads. Globally estimated to be between 400 and 600 GigaTons.
So compare with what we have of estimates left in our C budget
of about 375GTons. So they contain as much C
, than we have left to put into the atmosphere , before
we do irreversible climate change. Around 1000 Gtons released since
the start of the industrial revolution. There is difficulty in measuring this
potentail, due t permafrost. Occurs primarily in the N hemisphere
, as most land mass is in the north. Permafrost is a layer of
frosted ground that pretty much never melts season to season.
Methane is trapped in the frost as bubbles and in the micro-organisms in the
soil that is frozen. When unfrozen , will decay and release
methane and othe rC compounds , back into the atmosphere. Similarly with the
bubbles. Video of igniting and exploding methane previously
trapped in permafrost. We're already seeing permafrost melting
rapidly in most of the world. This is just the surface, way more buried
deep under the surface , trapped there while frozen. There is twice as
much C in permafrost buried , as there is in the entire
atmosphere right now. If we melt all the permafrost and put all that
C back into the armosphere, then a serious negative impact on
our climate. A positive feedback loop , that melting, C release, increasing
heat in the atmosphere causing more permafrost to melt.
We're not so sure how much C will be released when it melts.
Its so recent a phenomenon, we've not got good measures of it yet.
Organisms decay at different rates , some may not decsay, some
might re-activate and start sequestering C again.
Wet peat acts better at sequestering old c than has been emitted,
so could end up overall more sequestering than releasing.
The worst case scenario , the Clathrate Gun or Clathrate Canon.
A hypothesis that methane from permafrost will be released
and once released can never be sequestered back because the
offsets from revised peatlands will not be enough to resequester.
So we may already have set off something, we won't know
until its too late. There may be clathrate methane released from clathrate
mounds at the bottom of the ocean. They are under continetal
shelves, that s something we cannot deal with. But regards
peatlands we should now be ensuring we can sequester as mmuch C as possible,
we can help there. Mitigating against further peatland permafrost melting.
Peat is a good source of fuel, its C rich. People living in upland
regions, harsh environments, historically extracted it for fuel.
Then unintended consequences that so often come along with environmental
issues. To extract peat you need to drain it completely , the C stock
changes. Change 1 thing , there will be a series of knock-on effects.
Lowering the water table, damages the sphagnum moss , it cannot
grow, no peat accumulation, and total loss of the peatland habitat
and loss of its species. Instead of individual crofters, the issue now is
commercial extraction, less frequent but larger effect. Sometimes for fuel
or more often for horticulture.
So drains started on the sides , containing a raised hummock of
peat. Eventually the sphagnum stops growing as the water table is lowered,
C starts to be released. Forestry can take over peatlands as its very
flat , easy to work upon. Trees are very good at tsakig up water,
lowering the water table and peat growth stops totally.
Many thought planting trees in such places was very "green" but
ended up losing the unique habitat of peatland.
For agriculture again ideal landscape for likes of rice growing,
which needs flat waterlogged land. The worst comes from livestock
farmig , they graze nd will easily over-graze and trample
the key spagnum layer on the top. The natural slight undulations
will flatten out and loose structure, water table will
lower and trees and shrubs will be encouragesed to grow and again peatland loss.
Groouse shooting has had a large cultural and economic effects.
A large part of upland economy comes from grouse shooting.
To rais grouse requires a very specific management regime , involving
drainage, fires and sometimes kill off predatory species of the grouse.
Again you tend to loose peatland and get a heather dominated landscape.
Wildfires - benefits and problems.
Fire is part of the natural ecosystem. Fire causes a successional
change in vegetation. This can be benefit but also encourages the growth
of small shrubs and heather that are much more flammable than spagnum.
Try to set fire to a wet sponge. There are threats particularly , Malaysia, Indonesia
anf Peru, where peatlands are often near large urban areas.
So when they burn , very harmful air pollution to the humans.
Nearer home, Saddleworth Moor near Manchester burnt last
year. This highlighted the deposition of metals in heathland. When they burn
the metals and toxins are released into the air. Linked to respiratory
issues for the young and old particularly.
Wildfires are predicted to increase under climate change. We will
see more Saddleworth Moor events. The effects on peatlands from
climate change. Increase the temp of the atmosphere , the risk
of wildfires and peatland loss increases. Therefore more c in the atmsophere
and then more warming , positive feedback again.
Peatbogs are more vulnerable to drying than to warming.
However with climate change in the UK precipitation is likely
to increase in most areas. So in the UK would be beneficial
but in other areas like Indonesia likely to be detrimental.
Most upcoming effects wil bwe negative with climate change.
One threat is invasive species. If temp does change , it alows the
climatic range of species to encroach. Spagnum moss is what we want to retain
but is easily out-competed by othe rspecies. Reproduce quickly, spread quickly
and more likely to use the new resources that may come with climate change.
While peatland vegetation will struggle to adapt. Things like rhodedron
will quickly invade. Humans laying down pylon lines across
heathlands , is a good nursery for invasive species. They grow to a point
where they can then spread out. People inadvertently carrying spores
and seeds on themselves, and even domestic pets is an issuue.
A lot has been done and a lot of research, because they are so important
but so vulnerable. THey are so sensitive to change,
once humans start meddling , then unintended consequences.
Moist layer transfer, you take some acrohelm and sphagnum
and move onto areas to start the peat productiuon again. Things like
peat mosaics will start it of. If you can convince a farmer
to create such stepping stones for species to move acrsoo.
Also long strips of linear habitat within agriculture
improves connectance and reduce isolation effects.
Counter though is improve the connectance and you increase the
chance of wildfire and invasive species spread . So management
plans can have negative consequences.
Removing trees where they start to invade. Improving the
water table is important, will help restore dried out peatland.
Fires do break a dominance that can grow and give other species
a chance. We don't know what level of fires is natural
in origin. A simple remedy is just blocking drains.
Walking by humans and vehicle traffic can be managed
by boardwalks.
Legislation varies between countries, but protection of heathlands
is not number 1 priority. In Ireland there's no specific law to protect
peatland. Indonesia 2017 , protection legislation there was shot doewn be the
supreme court because of effects on local likelihoods.
As often 2 sides to these stories.
Some f the things you can find in peat bogs, Tolland man found in
1950 and he lived in 4C Denmark. His preservation is superb , due to phenolic
compounds . Bog-butter, people in Ireland used to bury theor
butter in peatland for preserving. It is sometimes found and dug out
and tastes like butter still. Plastic is preserved in peatland ,
including microplastic because its ever present now. Mammoths,
best chance of DNA cloning a live mammal from the extinct past, as
so well preserved a full genome from the body.
Q&A
With Cathrate analysis, with the melting of permafrost, methane would
be released. Some tens of millions of years ago, the Earth was a lot
warmer than today. You did mention it was irreversible but with the Earth
hotter at one point in time, if there is methane in permafrost now
doesn't it mean it is reversible and if the case, how severe if it does contine
to melt. ?
Its reversible in a geological timescale, but climate change only really
started in the 20C. If permafrost melts now then more than
doubling the amount of C released into the atmosphere.
As for if reversible, there isan intereseting argument that if we can stop it
from hap[pening at all. The world was very different 10 million
years ago, it was very different 3 million years ago. The current ppm of CO2 has just reached the
the level it was 3 mya, but the Earth was very different then.
Continue with C release and Earth will become something we will not
recognise. If permafrost melts it will go beyond the current situation.
For IPCC RCP scenarios , no consideration is made of future
permafrost melt and extra C release, it only considers human released C.
So worst case scenario would be entire equatorial belt countries being uninhabitable
and mass extinctions. By the time we could possible reverse it all , all too late.
We must keep an eye on it but the fingerprint to it will only turn up
after its started. Scientists go out there and test the bubbles for
methane. Peatland fires in Russia released such methan and the fires burnt for
many year, because so much of the gas beneath them. We should
be looking at peatlands for indicators , if we don't change our ways.
There was a period of 5 to 7 degree C warming during the mid-pleistocene,
about 800,000ya . That has been hypothetised to have been caused by this
clathrate release. So we've seen it before but it doesn't really
matteer if its reversible or not because we've seen it before and in that earlier
period something like 70% of terrestrial life got wiped out , due to that
temp increase. S owe want to prevent it rather than reverse it in the
future.
For the marine deep deposits of clathrates , is it normally kept there
by both temp and pressure?
Its the calcification depth . The threat is sea levels decreasing which will
not be happening.
Are methane hydrates a different process?
Methane hydrates are more like trapped gas but clathrates are solid.
It then dissolves and releases gas. In the mid-pleistocene it was
changes in sea level that caused release. Sediments on the continental
shelves were disturbed and as they fell , they shifted the deep ocean
sediments .
With the tephra layers , do they spread far and evenly enough for
you to sequence them like dendrochronology?
Thats what we use them for. Some eruptions don't go far
enough. You have to account for the fact that the eruptions that
do turn up tend to be very large ones . Sometimes the layers are so thin, they
are missed, in cores where you should be getting tephra.
That particular area could have been protected by wind shadow.
For pollen analysis, how do you tell the difference between say one pine tree 10m
away depositing pollen and 10 acres of pine trees 10 miles away? and pollen generally can
travel hundreds of miles?
Yes.
Some species have longer dispersal distance than others. By using pollen which
they know where its come from and work out what percentage of
pollen can be found in a core. Some pollen from grasses and
gramaloid? can travel very far. They know that if there is more than
5% of that pollen , then it indicates more long distance dispersal
than immediate dispersal. They can apply arbitrary units on whether
something has been dispersed far or just local, a reference.
What is generally the state of peatlands in the New Forset with all
the cattle , horses and people trampling around?
Historically I think the most effect would have been the rearing of
agricultural livestock. Nowadays they are stringent about what
is allowed on the land.
About 5 or 6 years ago the commission had a change of policy.
They started actively blocking some of the drains. Certainly in the
south of the forset, so the ground could be rewetted, not for any
agricultural reason. It has a greater conservation value and
significance as bog or semi-natural bog than it does as very
poor quality grazing land.
Would you know what is happening in the very North, Caithness
after the war, a program to introduce fast growing
conifers, big plantations of Sitka Spruce. Lots of drainage went on ?
Not specifically. I cant believe it would be good.
Basically juniper tundra , and when the wind got up , they just all fell over?
Unintended consequence. If people want timber they'll plant
forests.
You're not aware of any programmes to re-purpose.?
There are always vested interests involved .
Are you aware of our local mystery of the bog bodies found at Fawley?
When Fawley Power station was built 50s/60s. Men in white coats
took away the bodies. The official record has it they were bits of old wood
not bog bodies. Experienced groundwork crew , fullly familiar with
bits of old wood, recognised the leathery appearance. Someone contacted
the "Ministry" and instead of the men in white coats dumping the
so-called wood on the site bonfire , took whatever it was away and nothing heard
since. ?
(Ironically) In my experience you typically wear whitr coats to remove
bits of wood. It may have been considered a bio-hazard.
It would be posible that some experts would come along and take
away just pieces of wood for some further analysis, dendrochronolgy or
such?
Yes, entirely possible.
There's quite an extensive layer of peat under a lot of the
Soton area, deposited meso-lithic sort of times, at the Boldner Cliff
sort of ground level of human occupancy, now well under water in the Solent?
W 137
Tuesday 18 June 2019 Florentin Bulot, Soton Uni: Low-cost sensors for
monitoring air-borne particulate matter (PM), using Raspberry Pi .
The 6 St Denys monitors , including live data,
breathingspaces.org.uk/air-quality-data/
Every year there is about 9 million deaths associated with
air pollution. Thats similar to cigarettes. In the UK its associated
with about 40,000 deaths a year. What is special about air pollution is that
it varies from one street to another and time of day , like at rush hour.
That makes it hard to assess what people are inhaling.
Map of PM around the world, in the UK its not too bad compared to
some other parts of the world.
PM pollution comes from many types of sourcres.
Building and construction pollution is mainly fine PM.
Agriculture pollution is mainly from ammonia.
Fine particles are basically dust that is smaller than 10 micron.
Anything less than 10 micron is PM10. Anything smaller than
2.5 is PM2.5. They come from traffic, shipping , industry , natural
sources like dust/fine sand from the Sahara. So not necessarily
harmful dust, it depends on the source. The smaller it is, the
further into your body it can go and potential health effects.
In the UK the predominent source of the finest pm is the burning of
wood and coal, 38% whereas transport is only 12%.
Woodburning stoves have been promoted recently , but its becoming
the predominent source of fine PM in cities of the UK.
Fine PM when lodged in th elungs cause a range of respiratory
diseases, like asthma. In the blood can cause blockages of blood
vessels leading to cardio-vascular diseases. It is being linked to
diabetes and dimentia.
In the UK we have about 300 monitoring sites called the Automuted Urban
and Rural Network, AURUN. They are reliable monitors and its what is
used to show whether we are complying with legal limits. The gold
standard. It provides 2 kinds of reading , some are roadside
and some are background. Roadside gives us an idea of what people are
inhaling walking along that road. Bckground are located away
from any local sources of pollution , and give a more general
idea of the concentration in a city.
One of these stations cost 100,000 GBP to install and 3,000 GBP per year
to run. Only 6 such stations around Soton, you cant say this street is
worse than that street .
The sensors used measure the mass of the particles directly. The air enters and
is heated , because there is a humidity problem, hence different weight.
Particles collected o na filter , linked to a vibrating plate, the frequency
of vibration is linked to the mass of the particle. And so hourly data
of the mass of PM. Low cost sensors for PM work differently.
For fine particles , inside one is basically a laser and a photo-receptor.
So an optical sensor. Every time a particle pases in front of the
laser the sensor infers the number of particles. Then transforming that
number of particles into a mass. So not direct reading of mass , which
is how the legal limit is defined. Because of that , there are more
limitations. Its sensitive to aerosol composition in the air, its
sensitive to the concentration of PM. So if little particles , it is less
precise. Here we are measuring near the limit of detection so a serious
issue. Also sensitive to humidity and temperature.
The costs of these sensors are lower, the technical requirements
are lower , so can be operated by a larger range of people.
Because of that its possible to create dense networks of sensors
around a city. To start to understand what people are
actually inhaling. The reference stations are good to
have but to understand what people inhale , it only shows what a
person would inhale if he stood all the time near a reference station.
It becomes possible to identify sources of pollution . With a network of
sensors deployed around a city , you can start seeing pollution move
around the city and start to understand where its coming from.
It is important to involve citizens. The st Denys project is creating dat a
that people can relate to. There are mitigation measures we want to impliment
, but knowledge of hotspots/times is helpful in that.
It compliments the existing city network . But the big question is
what is the quality of this data produced, its reliability.
When can we trust the data the sensors produce , just knowing that would
be a great progress, but we don't yet.
Some readings taken at a site in St Denys bewtteen 24 April
at 4am to 2pm. Between 10 and 11 all the sensors follow the same peak
and then another peak later, they all show the same trend but looking at
each value individually recorded , there are big differences.
So these sensors are good for reporting a trend in pollution
but absolute values recorded should be handled wiht more caution.
These sensors cannot be deployed on their own, they need some electronics
for the comms, protected in a box .
So the solution I've developed to put the sensors out around the city.
The Pi takes power and has an internet connection via one lead,
its modular so can just swap out
a sensor. Today we're looking at PM but diferent sensors could go inr
there. If fine particles are no longer a problem in the city ,the
sensors could be replaced with something else and contine their use
for monitoring. There are 6 of these boxes arounfd St Denys to spot.
The public access plots are for readings every 15 minutres.
Difficult to interpret as different peaks occuring at different times.
If you see a truck passing , you can see if anything is happening on the plot
nearby. Shows the morning rush-hour peak, a peak at 4pm so perhaps school-run
then the evening rush hour till 7 or 8 pm.
Comparing my boxes to the reference station , the average of the 6 boxes
locally , they agree quite well in values. The box is waterproof
and removing lid ,shows the 10 sensors iin one box. 10 because of the
variability of output , the spread of data for different sensors.
We take the average of the 10 sensors and 6 boxes .
My earlier deployment was in 2 Soton schools. The reason behingd that study
was to compare different kinds of low cost sensors in a year long
comparison. The outputs are dependent on the composition of the
air being monitored and the time of year having more or less sources
of pollution. The cruise ship season is in the summer mostly
and winter there is wood-burning. We also wanted a wide range of
temp and humidity . One question we don't have the answer to
yet is are the sensors degrading over time, or do they need replacing.
So we compared sensors against each other of the same model and
different makes. We compared them against the reference station.
The 2 schools were St Johns primary school , French St near the
docks and Sholing school . Only one ref station in the city gives
PM2.5 readings which is the one we used.
At each school we deployed 3 boxes and 4 sensors in each box.
One box near the school entrance, one in playground and a third one .
Comparing the sensors against each other , the variation between
different sensors . If 2 sensors have a coefficient of variation of 0
then they perfectly agree. The threshold , from the US EPA is 0.1.
If 0.1 then good for fine particles. We had over 0.1 , close but over.
So 1 of these sensors cannot be used to monitor air pollution.
Thats why we moved to 10 sensors in one box. Was 4 ,now 10 per box,
it is also easier for us to do comparisons with 10. We still don't know
how many sensors are really needed in one monitor ,somewhere between 2 and 10.
We studied 4 types of sensors , the Plantower5 against Plantower7 and the
scatter plot is almpost a perfect line. Both from the same maker, different versions, PMS5003 type used in the St Denys boxes and LoRaWAN quarter-hour data feed for the
public internet .
But looking at other sensors Alphasens compared to Plantower5
there are 3 modes within the scatter plot. That shows if we apply a
correction method to one type of sensor we would need a different
correction applied to another type. These 3 modes are
partly explained by different responses to humidity.
They don't report the same values , in high humidity. Humidity doesn't
explain everything though.
The biggest difference between ref station and the sensors is that the
ref station is giving a reading every hour. While my ones are giving a reading
every minute. The absolute shortest time interval is every second , but that has a
lot of noise , so upped to every minute. All the city sites follow generally
the ref station . For that we've studied the correlation and obtained
? coefficient between 0.61 and 0.88 which is quite good for the sensors.
When we look at the correlation for different levels of background pollution
for the ref station fine particles below 8 . For the lowest levels the correlation
is less and above about 17 the correlation is better. So the sensors are
better at monitoring high levels of pollution .
25 is the legal limit here , so we want to be below that. So it is harder to
use the sensors in the UK , not that we can't use them, just harder to apply here.
So do the sensors degrade over time. So we looked at the correlation between
ref station , in different months of the study.
A pronounced dip on all sensors in August , but after that it returns.
For 2 sensors a straight line showing the performance does not degrade over a
year. For the AlphaSense one you see a lowering in performance. Maybe due to
dust accumulating in the sensor or component degradation .
The dip in Auguist has 2 potential explanations , the wind was mostly
blowing from the coast and we also see a general dip in correlation
for days when the wind was coming from the coast. Maybe more sea-spray
with the particles . The other reason for the dip was barbecues , around 6 or 7
pm and mainly fridays , I'm convinced registered barbies but were not
registered by the ref station.
These sensors can track very short lived pollution events , like barbies.
Also for fires in the city , like the Waterstones bookshop fire in Soton city centre
we could see it in the readings.
A reading at the Sholing school 25 August and the wind was blowing
between sensors , the peak registered on P2 can be seen a few minutres
after the peaks at P1 and P3, so giving a direction of track of pollution, in this case a local barbie.
If we take proper care of the data produced then these sensors can give us
more localised and persom=nalised data on air pollution. To understand
what people are breathing in , while travelling in the city,
because currently we don't know. Another concern, currently unknown is what
peole ar ebreathing while indoors at home.
It will be possible to monitor this high frequency data , wind direction and
data about ship movements and general traffic , then we can get a better
understanding of sources of pollution. We can interact with the populace
to act on air pollution , with the help of these sensors.
The current correction method we use. A paper only published last week.
2 ways. 1/ to know the characteristics of the p[articles , know the
composition, know the density and a few other parameters about them.
Someone else in Soton is working on this .
The second is mor eempirical , based on a regression model , based on
humidity and temp. At the moment no consensus on how exactly to
correct the sensor data.
The next considerations in my PhD , so the schools sensors, the st Denys
network , I'm intending to expand the network to get a better understanding
of pollution in the city. The intention is to produce a map of pollution
in the city. At the moment , the only maps are based on models
and only a few measurement datapoints. We hope for better
precision to the map , with the city-wide network of sensors.
One place of placement of sensors is within the port, I've an agreement with
ABP who are willing. Also sensors at Marchwood so we've an idea
of what is upwind of the port as well as city side of the port.
I'll be characterising the sensors in the lab , controlling the air composition
, temp and humidity . Up to now all my sensors have been
some distance from the ref station and hoping I was measuring the same.
I'll be placing some of these sensors in Vietnam and Morocco. where there is
higher levels of pollution and the sensors would be more reliable there.
In Morocco there is a lot of dust from the Sahara , dirtier cars with a differnt
sort of fuel to here. A totally different environment, and so better to
understand how to correct the sensors.
Q&A
When you described the sensor box you had data and power along a cable to the
box, but also a wireless antenna. Why 2 data routes?
Every time we are studying a sensor , we need to find a local internet
connection and drilling thru walls, all rather messy. This is a back-up solution to
collect data. With the LoRaWan network you can only send little
data, the maximum rate of output we ar eallowed is every 15 minutes,
sending just the average. Ultimately want to get rid of the hard-wired internet connection.
You don't have an SD card in the Pi?
At the moment 15 locations of these boxes and 150 sensors so I don't want
to go around opening boxes and collect SD cards.
But wouldn't the SD cards store data for each of the 10 internal sensors every minute?
Actually every second . With the wired connection and SD cards we get all the raw data
, but in the end , when we've sorted out sensor correction it will be redundent.
Say you find sensor6 is definitely erroneous you can ignore its data rather than
have it contaminating the average output?
In the end we intend to reduce the number of sensors , currently these are boxes for
testing proposals. Another project just started is how to get this box smaller
. The sensors themselves are low cost between 10 and 100GBP but the whole
box is 1000 GBP. The project just started 2 weeks ago would only have 2 sensors per
box.
Do the sensors have a fan, or natural ventilation?
The sensors have a fan , very small , but otherwise no fans. We could have a
fan , but cost and power consumption goes up. At the moment consumption is
15W .
What about contamination of the sensors , they must eventually
get dusty.?
Yes, thats why we wanted to study degradation. When you open up thse
sensors after a year you see see dust in there. The sensors are facing
downwards , so dust tends to fall off .
When i first came across this project i thought you must use reference smoke of
some sort. Plumbers and gas-fitters use test-smike for checking flues and
chimneys. They set fire to a little preformed tablet of something that
generates blue or orange smoke. I'm assume the smoke output is fairly
standard in its gradation of particle size. But you don't seem to use a standard reference
smoke at all, for initially setting up these sensors? Perhaps set off one in a metre cube box with a fan and introduce to a sensor?
You are purely comparing to the ref station in the city?
There is no standard smoke in a can . Some studies use incense , some use cigarettes,
polystyrene vaporised and Arizona Dust which is becoming a standard
in the USA, basically dust from Arizona . But no consensus on any
standard dust or smoke. NPL produces gases in cans for standardising and are
just working on cans of standardised smoke. What you said is what I'll
be doing in the lab . Placing a number of boxes in an hermetically sealed environmental
chamber and introduce some PM. I'm not settled on the source of PM
that I'll be using . Also varying the humidity and temp inside the chamber.
Do you have any problem with condensation inside the boxes in UK winters, causing problems with the electronics etc.?
So far no problem. So far I had to change 1 of the 6 . The boxes are warm
from the electronics inside and no condensation issue.
We are running the LoRaWan network, the base-station owned by the uni.
One of those we opened and water flowed out of it, but not these sensor boxes.
Assuming you get the number of sensors reduced and overall cost less,
where do you see the uptake of them? Informing public policy perha[s?
There is a website where you can find the cleanest walking and
cycle routes , is that the sort of application?
Thats one but also public bodies generally , checking that measures
they take actually work.
The council is considering a clean-air surcharge on vehicles entering the
city. So they will only be tackling 12% of city pollution at the best?
There are groups involved with air pollution but so far have
had little data to underpin any actions. If say a group gets 200
residents to go to the council , over some measure to take .
There is "clean Air Southampton" I work with. All the readings are
publically available on the breathingspaces website for this St Denys project.
Large ships in the docks and the container port straddle carriers
ar eworking 24 hours a day. ?
We don't have actual measurements of it yet. NO2 pollution is mor elinked
to road traffic. For shipping its NOx, CO2 and SO3. For NO2 ships are
less significant than cars, just by the models, as we don't have real data on
it. Ships burn much dirtier fuel, so PM output can be much more
toxic . So say the pollution from ships is 5% it might be mor e
harmfull than tghe other 95% around the city.
another uni group is collecting data via a different monitor, like a big
vacuum cleaner, er inside and do a chemical analysis on
the filtered . Thet found there were more harmful particles in the summer
than in the winter, work in progress .
Do you measure the temp thru the sensors as well?
Yes and the humidity.
Why did you go for PM rather than gas sensor?
Gas sensors have been more studied, spo for PhD purposes it made more sense
to go for PM . Gas or PM need completely different techniques , so I
had to concentrate on one only. And fine PM is the more harmful
part of pollution , compared to gases. Now we are cleaning up the pollution process ,
ridding larger PM,
fine PM will come to the fore.
There is no regulation at all at the moment for ultra fine particles, quite concerning in
my view.
Have you picked up pollution from other places? I was looking at your local
data and one night about midnight there was a peak at about midnight but nothing on
the other local boxes. Then i was thinking, the same with the one on this hall,
its quite near a gas-burning boiler flue. Do gas burners output PM?
Yes , any combustion process will produce PM. Its also possible for a sensor
to be simply wrong.
Do you know how far such particles do travel, say from a major fire say in Winchester
and the wind coming from that direction?
Some people in London can phe signatiure of ships ick up , all the way from
Soton. It may be just traces , but it can be found.
I was surprised to see that on one random sampling weekday day recently that
161 diesel trains passed thru St Denys.
What about the big petroleum industrial complex at Fawley?
Its upwind of the city so yes. There is a big mix ofg sources of pollution in
Soton. Traffic, the port, airport, Marchwood incinerator, Fawley
refinery. Its not good to live here but its useful to study pollution
here. It makes some sort of sense.
I was doing this sort of thing about 30 years ago , our low
cost sensors were over 5000GBP 30 years ago. It emerged that
November 5th is the time that industry burns anythng it possibly
can . We had 3 sensors around Fawley and nov 05 stood out. ?
A study in Amsterdam found similar peak at New Year.
I'd not thought about people deliberately burning nasties at those times.
With your high frequency data have you found anything that could be precisely
tied down to say planes passing over or mainline train service at a regular time,
repeating?
My work is to characterie the sensors and less to make sense of the data.
I don't have the time to interpret the data for that sort of purpose,
much that I'd like. I'm sure it would be worth somone trying to
correlate repeated minor peaks with say a regular diesel train service.
It would need a longer tmeperiod of 2 years or so , to rule out
other possible repeating factors,. The high frequency data is available on request.
Are we supposed to discourage friends and families from having barbecuses?
Yes ,and wood-burning stoves. Even the best such stoves , one such is equivalent
to 6 trucks running. All very dirty but its good for the environment
in the sense of being C neutral. Unforseen consequnce again.
Ships burning gas rather than diesel is better for pollution
but not necessarily for the climate. The average distance of a car travelled
in a city is less than 1km. Do we need a car to travel 1km or could we
just walk.
Tuesday 16 July 2019 Dr Christine Currie, Soton Uni Mathematical Sciences: The Mathematics of Pricing
The work we did on ferries was with Red Funnel in Soton. No commercial price sensitive info here, they liked our vehicle packing info but they have other ways of doing their
pricing. We initially worked with P&O ferries bu tthen we moved to
Red Funnel. Most of this maths work relates to Red Funnel but it will
be generally applicable. S opricing according to ease of packing and increasing the
efficiency of the packing. Awhole research area described as cutting and
packing originally relating to minimising material wastage for cutting out dress
patterns. We will be using the similar techniw=ques for optimal
packing of vehicles on to a cardeck of a ferry.
Big vehicles take up lots of space and awkward to pack so you might think
we should charge them more. Often the big vehicles are freight that come
day in, day out all thru the year. So charging those users a lot of money is
not necessarily a good idea. Wheras tourist traffic is just for Easter break say,.
Red funnel has a ferry terminal in Soton and run to Cowes , Isle of Wight.
31,000 sailings between mainland and IoW and back.
3.4 million passengers transported and about 873,000 vehicles
since 2016 and still increasing , so they have introduced a freight ship as well.
In some ways that has solved some of the problems as that means they can rid
some of the awkward trafic onto the freight only ship.
A related problem is how to arrange the cuing of vehicles on th eland
prior to embarking. There are also WightLink ferries and hoverspeed hovercraft
services to the IoW, so there is competition. There is pros and cons for
choosing relating to road access on the mainland. Soton is easier to get to
but a longer crossing time. So how canwe improve efficiency for Red
Funel operations.
RM= Revenue Management. How to maximise revenue by dynamic pricing.
RM appeared in the 1970 for airplane costing after deregulation of the
airline market in the USA. Prior to that prices were highly regulated and
you could not vary them much. Low cost carriers came in and American
Airlines had to compete with these low cost carriers.
So they started to put conditions on their cheap prices. They could sell
tickets for the back of the [lane cheaply, undercutting the competition
because they knew the high payers would then carry over for the whole operation.
Its easier to imagine this in terms of planes than ferries, so the diversion to planes.
Planes have fixed seats and csan only have 1 person sat on 1 seat. They take up the
same seat space whether in economy or business class.
We know we have X seats to sell on this plane. THere is whats called
perishable inventory , meaning after the flight has gone you cant sell it again.
There is fixed capacity, very unusual for a carrier to find another plane
of squeeeze in some more seats. Then the allocation problem we are trying to
solve. If we charge nothing, the demand for those seats will exceede
the supply. So more people than seats, if not, then it becomes a different
problem. So how do we set the prices so we get the right number of people
on the plane. Set the price too high and I wont sell all theseats.
Set the price too low and there would be people who would be prepared to
pay more are paying a lower price. What price do I offer and when.
For dynamic pricing we are changing the pricing going thru time. Its
not one price for the whole season , typically it increases. The close rto
a time of departure, the more a person is prepared to pay. There is
randomness in there, how many people actually turn up for a flight.
More people will be thinking of purchasding nearer to departure time,
giving a peak. That peak will move dependendent on whether a leisure
or business flight. We know that but we cannot quantify how many
will turn up for that one flight. Forecasting comes in there and also
statistics. To get a feel for what this variation is. Also getting an idea
of what people are prepared to pay and how that varies with time.
Then 2 questions almost the flip side of each. What price do I offer
and when , then how many seats do I offer at a price. So we can have 2
different models, one the price varies over time, and the other a set
of price points and a set of seats I will sell at those prices. Closing off one
price point ater selling so many. As a consumer all you see is that the
price keeps changing. We tend to look at dynamic pricing, the price changes.
Customers arrive into the system , so they want to buy a ticket. We assume this a
is a ??? term,
random process with a time varying rate. They arrive randomly but price
changes over time, generally increases closer to departure. Thats while people
think of buying , check prices of competitors , phoning up for offers etc.
Then another term , the probability that they purchase a tickeet. An asumption we
make that this is dependent on the price being offered and the time at which they
look. The closer the time to departure, the more likely they will buy
at a given price. The highr tthe price, the less likely they will buy.
There is a term called Reserve Prices , the price you have in your head
,the most that you are prepared to pay, say 150. Someone else would have a different maximum in their head of 50 and someone else a maximum of 500.
So a distribution across the population , Reserve Price is related to Probability of
Purchase term. We cannot see these prices in their heads, having to rely
on historical data for that, a tricky problem. So you will have some
distribution of prices and rates lambda of t, then we need a method to
optimise the revenue ,for given prices. With the important capacity
constraint , you wont get an infinite number of people buying.
The problem and the assumptions going on uinderneath.
Now look at packing relating to ferries, a bit like playing Tetris,
then how to combine the two.
For a Red Funnel ferry , the drivers drive on and drive off, RoRo ferry.
No turning round of vehicles. There is a mezzanine deck which can be
raised or lowered , dependent on what turns up and can be altered between
sailings, quiote a quick process. It increases capacity for smaller cars.
You effectively get another lane of cars. The space below the mezanine is quite
low , limiting what can be placed there. There are 2 of those mezanine as one on
each side. To choose to use 1 or both of those moveable decks is another
optimisation problem. There is lift acess and some vehicles need to be
close to the lifts for people who cant walk far. There are lane markings on the
decks which makes it easier to solve packing but reduces the efficiency of
packing . A free-attack to the problem of different width vehicles i easier without
lanes. We created 2 solution versions , 1 with lanes and 1 without.
This is the main deck which has mixed traffic, then the top deck
which is cars only. Less interesting as the cars are much the same size. Even so
its possible to squeeze 1 more on by parking it diagonally.
Most of the traffic to the IoW comes on the ferry, so supermarket
delivery lorries, building supplies with width overhanging loads ,
and even large yachts on trailers. There are prison vans with special
requirements as the prisoners are locked in during the passage,
so they have to be placed under the sprinkler system . Sometimes hazardous
loads cross. all sorts of complications. The loads on the main deck are
kind of rectangular . Manoeverability has to be taken into account
, so some spaces cannot be used because of turning circles.
The experienced loaders sort this all out in their head, but have a new loader
and you can see the packing difference, less vehicles loaded on.
So some of our product is for training of loaders. Gives them some practise
before they get started for real. There are 2 ways of looking at this and relates
to the painted lanes. Called the Exact Way and a Simulation Heuristic.
When selling tickets and looking at packing , how do I define the space of a
vehicle. The way of solving , by the most accurate process is to say
I've 3 of type 1 , 2 of type 2 and 1 of type 3 and 4 of type 4.
Each number is effectively a dimension . As you get to 20 different vehiclr types
, which Red Funnel easily have, then you have a 20 dimensional
problem which gets huge to handle as a huge number of vehicle
combinations to fit. So this works , but grinds to a halt over a certain
number . For a 1D problem of fitting to lanes , each lane is a bin
and we're packing htose bins as efficiently as possible.
The other way , allows for all the complications of a massive number of
vehicle types. Instead of this number of each type of vehicles , we look at how
much empty space we have left. Thats how we can define the system.
This speeds things up because we've 3 dimensions . So you have some
area left, what if I pack a big thing next , will I still be able to put
it on. This is why we have simulation heuristics. This packs across the
whole space and not constrained by lanes , makes it more efficient.
The equations
The exact method where we are looking at the numbers of each vehicle
type. To maximise useable space we call U, U is space that hasn't been
trapped between 2 lorries. If vehicles were at an angle you would
end up with unusable deadspace between. We are looking for useable space we
can park something in. Plus a symmetry breaker, which increases efficiency
, otherwise if you have lots of lanes all looking much the same , the optimisation
gets confused as to which lane to place into. Its an integre program as we're looking
at integres. We have integre number of variables . All the terms are linear as they
are linear in the variables. Such as a given weight is one variable.
So we are trying to optimise amongst a lot of constraints.
1 constraint , I;ll have to activate an extra lane, a "big M" constraint.
Basically its saying try not to add he extra lane if you don't need to.
2 constraint, limited to lengths, cannot hang over the edge at the end.
3 use the lane with most space available, use it sparingly.
On the other side is the simulator, it doesn't have a set of equations in there,
less mathematical in a sense. Looking at how the ferry is being loaded, looking more heuristically, for optimisig. Its assuming ??? loading on to the ferry, it has the lanes on
the upper deck and then the 2D packing problem on the main deck.
Where our main interest is with the bigger mix of types.
For the simulator, like human loaders , its assumed to take account of the
real world constraints mentioned, lift access , mezzanine deck position,
dropped trailers (lorry beds without traction units which are left on-shore and use the ferry
companies highly manoeverable tractor units) , reverse gaps where something has to slightly
reverse before puilling out. The result is a quick and effective method to optimise
packing efficiency for any particular set of loading types . Also gets used to
prevent over-selling , what we and RF would like is iif they sell a load
then it will all get on the ferry. Having such a simulation package , it
can also function as a training tool for loaders, loaded on my laptop to play with.
Its calculating the remaining space that can be used. It moves the shape along and
calculates the remaining space , the sum of the rectangles left behind.
The heuristic element loks at all the vehicle types that re there on the
dockside . For each of those types it looks at where I could load it, for the
best placing. Then which vehicle type to load next, its not caring where they
lay on the quayside. It assumes it can get to any of them at any
place in the queing on the dockside, that is the next piece of work for us,
where this becomes a constraint on accessibility prior to loading.
It makes its decision by looking at various arttributes and run lots of times
with lots of different scenarios and see what weight we should give each of the
attributes. Tightness is a factor, packing a vehicle in where it just fits
rather than having lots of space around it. Space loss due to stagger parking,
needs minimising. Overlap adjascency ratio ???. The weighting factors we do as
a result of data done in advance. If we are running it for real we'd have the
weightings in there , sum the result and pick the one that works best.
Part o the process is a simulation annealing algorithm.
Q: There is no issue around mass balancing the ferry, say all the lorries on one side?
There ar eissues like that , the most recent version of this has a centre of gravity
that moves around and is output as a visual display , but its not really part of the
optimisation as its not a massive problem as the ships are quite heavy in itself
and they don't know how much these lorries weigh. They ar enot weighed o nthe
dockside, a lot is what the driver says . When we first showed this program to the loaders a
few said we wouldn't do that configuration because all the lorries are down one
side. So we try and balance a bit better. Also if you load something heavy at the
bow , then the stern will rise and can mess up the loading ramp positioning.
The CoG doesn't move around a great deal.
So we've maximised space and now the pricing objective. A decision
variable would be the price offered to each customer and type of vehicle in
each space in each time period. This is how I define space comes in.
Having a nice clear description of the space is important as this will
affect what we know and what we think we know about the system.
Then the capacity constraints , we also need to know whether we can fit these
vehicles on the ferry. Unlike the airline example of 100 seats and so
100 tickets can be sold, there is an area constraint . They can overbook but thats another
talk. With a ferry you can overbook if the estimate is not right. We need a
reliable packing algorithm to allow this.
We split into lots of discrete time periods and go with one booking into each
of those discrete periods, that assumption makes the maths easier.
Q: A minute time period?
The whole selling period is about 1 year. Each discrete period tends to be a
few hours long but it depends on demand. High demand leads to shorter period.
So at least 1 cutomer will buy one ticket in that period. We ignored complications
like group bookings , which tends to be rare for a ferry.
So the model may have a couple of empty time periods where nobody
turns up , then a car with a ticket turns up. Then you have to decide at this
point , an empty state how much time is left, you know what price you
are offering for that vehicle type. Wiht ticket purchase that changes the
the status of that discrete period and that may change the price to the
next offering. You keep going like that and at a later period you
have a probability of a certain type of vehicle ticket purchase.
2 things can then happen buy or not buy. So a tree-like structure ,
does something turn up, if something does turn up it may buy or
may not. You are loking ahead and how you set your price is then
dependendent on how much you coul;d get if you didn't sell to
that person. The technique we use there is Dynamic Programming
, its looking ahead to what could happen . My expected prifit
at atime t and a particular space, I'm trying to find a price that maximises
that. They arrive at a probility lambda(v) for v vehicle type
and this one will purchase with a probability a. If they purchase I
get an immediate revenue P but it won't be giving me any revenue in the
future. The next time period has the same equation
but it will be in a different state as one vehicle space is sold.
This is sort of the opportunity cost, the cost of having sold that ticket
in that time period.
The next situation is arrive but not purchase (1-a ) probability in which
I'll progress to the next period but will be in the same state.
I'll be one step ahead but the state remains the same.
Also a possibility of no one turns up and no purchase. Dynamic
programming can look at this sort of situation very efficiently
almost working your way backwards to get to the answer.
The diagram of the probability structure. If we get to
high price and we're a long way out , very few people will purchase.
If at a low price , even zero , and right at the time of departure
people are more likely to pay.
The exact packing with hte slidefull of compound summation
equations, can be high dimensional for all vehicle types and ccan
be long computer time. We use that set of equations to
define a Pareto? front, where if we put 1 more of any vehicle
on that ferry , then it would be overfull. This is the efficient vehiclre
combination and there's no point in looking outside that front as we
know it will not fit. This limits our safe-space being able to work out what that
is. With the lane structure formulation we use the heuristic structure
when we are a long way departure, we don't need to solve this big
complex program. Only nearer capacity or departure time do we need to
worry about solving the exact equations.
If there are 2 vehicle types there are 2,271 different states . 5 different
vehicle types its close to a million and that is reflected in the time
to crunch the problem. We can solve quickly for 2 but increase to 5
then solving the combined packing and pricing problem the processing
time is getting huge. Go to 20 and its becoming impossible.
The expected revenue , you get better returns if you split the
vehicles into a higher number of classes. For 2 classes , we say anything
less than that size iclass 1 and bigger than is class 2. So you end up
putting 5m vans in a class that goes up to 11m and a lot of wasted space.
Thats why we get different revenue results. For 3/4/5 types we can get a
reasonable revenue from the eact solutuion. For the heuristic one and packing
over the whole space rather than just lanes we can get much higher revenue emerging.
It givesa more efficient atack and a more efficient understanding of what is
going on.
Another project was with a big E-grocer 5 or so years ago before
delivery to your door had taken off. We wanted to have cutomer
based pricing optimisation as to time slots of delivery. We wanted to
encourage customers to pick a slot where the a delivery van was already
delivering just down the road. Imagine being i na far off village
then you would be given a cheap slot if you chose similar time to
a delivery to a neighbouring village.
A www page showing the green vans showing the most efficient
slots. A customer would get a whole suite of options for times
and also include green-van slots , with hte prices .
How can w euse the price and maybe the green-van to
encourage people to go for slots that are beneficial ot the
deliverer. Cheeper , more efficient and generally better all
round. So we had to build a model around how a
customer veiws the slots. We would design a tentative route plan
based on the forecast and then inserting the cost of an additional
drop. Used an almpst identical Dynamic Program as the ferries one, just there
was a cost function in there , how much cost to serve that 1 customer.
So modelling customer behaviour, how would they choose between
slots and would they purchase if the delivery cost was too high.
So optimising, then update your forecast routing plan as a result.
So almost the same method as the ferries but on a completely different
problem. These programs improve outcomes, but only based on
simulations, so who knows what happens in the real world.
Sometims a high-value customer would get a negative delivery cost ,
because you could haul them in and keep them shopping with you as the
overall profit is worth it, and also ensure they are in the slot you
want them to be in.
Future work ;- ferries again but multiple drop-off like Channel
Isles ferries, or Scottissh Island ferries where there is a sequence of
drop off at different ports and also other traffic comes on,
all potentially out of sequence. Put something on for a short hop
and you've perhaps lost space for something to doa long journey
as well as the packing problem.
Air-cargo is another one , you're never sure what will turn up
with air cargo, very uncertain so a lot about balancing uncertainties.
Delivery of large awkward shaped packages , so can be plant-hire
vehicles on the back of a lorry , like diggers and ecavators, how do you
do the deliveries. A nice one will be how to deliver packages to
space-ships. For a future with more commercialised activity up there
how do you price the delivery of such material, you've the weight , the
volume , watch this space.
Q&A
As a non-mathematician , seems a lot of the parameters you're wrestling
with overlap with the container business. I know they have a fied box
, but they do vary in size , and fridge-box containers , multiple
destinations . ?
The regulariy of containers makes a big difference, although there are
differences in size , its not too different. There is stacking as well
though. It comes under a big category called rectangular packing.
Drop trailers problem?
Therre is an issue about how many such trailers you put on a
crossing because RF has had problems with not enough time to board and clear
lorries in the turn around. Drop trailers are kept separate and only a couple can
be moved at a time.
The booking system should be taking in info about your car or vehicle including
dimensions and place straight into the program?
At the moment they give everythinhg a car-equivalent unit and they will look
at keeping that nimber below a certain level , somewhere aroud the 200 mark.
They know that if they had loads that was all cars ,they cannot fit them all
in with that number of car equivalent units. If they have a mixed load they
can fit them in a bit more easily because they are a bit over-generous on some of the
car eqivlaent units. Thats the model they use at the moment but its not
perfect .
Can they refuse a booking and wait for something better to come along?
We are trying to use price as a lever, so if something big comes along and its looking
quite full , then they will see a high price. So a maed out pricing.
Its rude to say no but set them a high price , thats acceptable.?
Yes
Presumably there's a sort of mathematical relationship between supplier
and regular customer on that as well. those customers will have some
insight as to when they will get a better price or some sort of feedback perhaps.
Wheras an onspec car customer would not have.?
Definitely. The regular customers are looked after very well. Other than
freight contract, most of them are island carriers so they will see
slightly different prices going that way. Game theory comes
into this .
Also an element of c-operation as well as competition?
Yes. There are ways of modelling those interactions. We've not done it
here but generally yes. It varies product to product , how important
those interactions are. There is a perhaps mythical story of a
USA professor who would try and book flights that he thought would be
over-booked, so he could get free airline vouchers. The worst that could happen
is he'd have to fly somewhere .
Have you looked at digital ? pricing ?
We've looked at pricing for web pages , clicking-on and also
radio adverts. Radi9o is quite highly regulated and restricted on the
number of assets you can fit in.
Is there rule-of-thumbs with the time-served loaders knowing say a particular
vehicle type turns up , they know a load of motorbikes can go in a specific
space next to it, that sort of knowledge base?
Yes they know a lot of that sort of thing. We keep saying we're
not trying to do them out of a job . They will even assess you as a driver
as you drive up as to how tight a spot they will put you into.
They must have collected data on regular users. Can they look that up
later, yes we know this vehicle , we know this driver?
No . I think its more assesment on the day.
So not a customer database?
There is but not used for loading purposes.
We're trying to develop something so the result works like how the
loaders would fit . They know what they couldn't do , so when it comes to
setting the prices , then yes or no. And also for trainee loaders.
I'm always surprised the short turn-around they have , 55 minute crossing
and most of the time 1.5 hour with turnaround at both ends, no
spare ship to call on. I've never seen breakdowns causing problems or
other issues?
It can happen . At Cowes in particular they are trying to improve
the situation there . The loading yard used to have a road in the
middle of it, and their vehicles had to cross it.
Also vehicles coming off the ferry went in front of vehicles boarding ,
so no loading and unloading at the same time. so they'd load the car deck
while unloading the main deck for eample. They're currently redesigning the
Cowes end.
I've a motorhome ,ring up to go to IoW in July
then something like 300 GBP return but book a weeks camping and
bring my motorhome then about 90GBP, etraordinary gymnastics in
pricing. ?
Yes they have arrangements with different companies on the island ,
the loyal customers bit. The campsite becomes the customer and not you.
We did some related work on customer lifetime value . Then the switch point
between RF and WightLink say.
Any eamples of loaders doing favours for their friends?
No , none seen.
For the airline problem it used ot be , start with a high price , then
effectively a Dutch Auction and a standby price a tthe end. Your work
seems to be much the same as all online retailers and travel companies have
these days. That then obviates the need for standby pricing or still
a role for that , if unfilled capacity at the end, sell at a cheap rate. ?
It often depends on the market , its knowing when is the last
minute for airlines . You could have someone who really needs to get to
a meeting and they may be prepared to spend 5000 for that, right at the
last minute, but if you sell it for 200, you've lost , so its often orth keeping it
for that high price , perhaps 1 time in 100 one will appear but
onaverage you're no worse off. Its balancing off the probabilities
and the costs.
For your dynamic programming of pricing, how dynamic is it in
allowing someone to input new variables if something changes like a change of
fleet freight operators .?
I had a PhD student who had a project estimating these models as you go along.
If you have pricing models , say entering a new market or the market is
changing , what prices do you put out inthe market. So you are learning
but making money at the same time, so you have to be strategic as you'd
like to know their reaction to any price. Charge something crazy you'll not
make any money. Then the parameters get updated.
How low a level of staff can change your programming structure?
They would tend to be updated automatically via management systems
constantly feeding dat ain .
You don't have to have a coder come in?
generally not , only if the logic of the process changes.
The pricing algorithm is looking for strange behaviours. Like
every year there is a moped festival on the IoW , can RF all of a sudden
get all those on one ferry.
For the ioW music festival there is a lot more car traffic but because of the
demographics for that , they tend to be smaller cars so can get more on.
Not big family estate cars. Things like that, the model cannot capture
but they will know about certain special ecvents.
Tuesday 06 August 2019 Dennis Doerfel of Reap Systems , Southampton:
Developing hybrid marine-diesel/electric propulsion systems .
2 presentations
first is the concept of hybrids, second is results of the ferry deployment we made
in Falmouth, Cornwall.
In 2015 I met somone at a conference and we discussed what we could do to
improve marine transportation, and he said about the hybrid concept .
We started in Venice , thousands of boats in Venice busily polluting the
water and the air, smoke and noise. We started with the Venetian
taxi boat , that can carry 10 to 12 passengers , usually from airport to
the centre of Venice. This Venetian taxi boat is now in Soton. We converted it
to hybrid , so we could learn about the technology . Its 9m long, not
very tall so it can go under Venice bridges. About 550 such boats in
Venice. The second Falmouth project we had a number of
partners including government funding.
Reap systems is based about 10 minutes walk from here on the river
Itchen. We've been passionate about electric cars for a long time
, buying my first one in 1998 and decided on this area as a career ,
doing a PhD in soton on Li-ion battery tech for cars. We started the
company in 2003. Other projects with another company in Farnham which
makes motors that sit inside the wheel, and we supplied the battery
tech and integration. That car was 300hp and are mainly in China now
because Chinese bought the company. Since 2004 we've supplied
systems to a German company that makes electric boats , many lakes in
Germany are not allowed to use combustion engines on them, they must be electric.
For the hybrid boats we made the whole system , excluding the
manufacture of the engines. We started with electric cars but as a
company we're too small an operation , so we decided to move into the
marine market. We made a small electric RIB and put it on the
boat show in 2013 to gauge the market. Everyone loved the boat
but no one wanted to pay for it, too expensive.
One problem with e-boats is the price of batteries, although coming down now.
Benefits are , no local emissions , even in global emission terms it is lower C
than combustion engine. It is near enough silent , regenerative breaking
is possible , on slowing down some of the energy can be back converted
to the battery, it is very efficient. Another advantage is if you want to rely
entirely on renewable energy , most people would go for electric
not liquid fuel . Take solar or wind power generation or other renewable
structures go for producing electricity first. I*ts moree efficient to
store in a battery than to create a liquid fuel as the energy store.
It is possible to produce methane from CO2 and energy but its not
been widely adopted yet, likely to come soon.
Diagram showing different energy storage devices , for storing in car or
boat for the propulsion. on one axis the energy density how much
energy for the weight versus the power density . Different battey
types on the market , some are high energy batteries for e-cars like
Tesla and a very high energy density but the power density is low.
For a hybrid car you would aim for high power density but you
don't need so much energy. In 5 years ahead this performance might double.
At the cell level 690 W-hours per Lt but at the battery level of combining lots of
cells about 400. Comparing that to diesel fuel , instead of 400 it is 10,000
,so you can store a lot more fuel . That may not be a fair comparison I
thought as a diesel engine is not very efficient compared to electric motor.
Allowing for the lack of efficiency it comes down to effecdtively something
like 4,000 for storage, but its still a factor of 10 better than for battery.
Hence the impetus to consider a hybrid , battery for short distances around
town with much breaking and regenerative recharging but use liquid
fuel for longer journeys.
The speed profile of Thames Clippers in London , on some parts of the Thames there
is a speed limit of 10 knots but other parts up to 30 knots. The boat needs a
lot more power to do 30 kn that 10 knots, not linear , not 3x more like 10x.
For 30kn the battery would have to be enormous but at 10 kn diesel is
very inefficient as its not operating at enough power output. In between there are
stops , a long stop at Greenwich and often the diesels tick over continually there,
to keep the generator and other auxillaries running..
So for a hybrid , run diesel mode when fast running and charge the batteries
and then for slow mode run on electric only, no diesels running and the battery
will supply all the auxillary power needs while in that mode.
But the question is will there be a fuel saving. So could there be a fuel
saving. The efficency plot of a diesel engine , pretty hard to find.
Everyone uses diesel and a lot of talk about efficency but try and get an
efficency plot from a manufaturer, virtually impossible.
Shows the rpm of the diesel, between idle and max rpm.
Shows the torque and the extra curve shows what the diesel is capable of ,
how much torque it can produce at different rpm. Shows up lines of
equal efficiencies, so the highest efficencies at specific fuel consumptions in essence.
So how much fuel does it consume to produce 1KW-hr for example.
The most efficent area is at a relatively low RPM and relatively high torque.
From that area fuel consumption goes up. A factor of more than 2 across
the plot. For a boat , has a propellor, and will run at any rpm
and the boat will accelerate. There will be more torque and more thrust on the
prop. So run the prop at idle speed, you have a torque and it follows
the curve up to full speed of the engine. The aim is to end up at the
maximum power point , because people tend to want maximum speed.
There are parts of the curve where a boat hardly ever operates .
Most of the time a diesel would be on the curve that is far off the
optimum. A simpler diagram just looking at the prop curve
, what is my fuel consumption at different rpm, high fuel consumption at
low rpm , medium rpm is good and then at high rpm it goes up again.
Most boats are operated around 80% maximum, the better
parts are not used routinely.
So for the Venice taxi boat its got to go really fast ,about 30
knots near the airport but in the small canals 2,3 or 4 knots.
So the boat will be operating in the non-efficient areas for very
long times. So the idea is to operate one section on electric
and diesel for the other section. When you operate on diesel ,
you will recharge the battery. So what is the effect on the diesel operation.
Running the generator forces the diesel up into a more efficent operational
zone and that works.
There are different types of hybrids in the marine industry.
Simplest is the diesel boat with engine and gearbox , prop
shaft and prop. Then we are working with mechanical power all the time.
Series-hybrid is the next easier. Electric motor and mechanical
power , gearbox, prop shaft and prop. To run a motor from a
battery you need an inverter because the battery is DC and you need
3-phase to drive the motor. The battery will be empty at some
point . The engine is diesel usually in boats , electric motor working
as a generator , with inverter and charger . Series hybrid because you
have to produce electric power first and then use electric power to
make mechanical power. On big ships there is already big generators
, for them to add a battery would not be too difficult.
The disadvantage of series-hybrid , from fuel you convert that into
mechanocal power, convert to electric power, convert to dc power,
store that as electrochemical power , take it back out and convert to
ac electric power , to mechanical power, convert to lower rpm ,
convert to thrust. A lot of conversions with losses each time ,
so potential fuel savings are probably eaten up in all those
conversion losses.
The parallel setup tries to overcome some of these issues and does look
a bit simpler, although more difficult to impliment.
Normal diesel enging, gear box , prop shaft , in between is a
clutch and you can take mech power off and connect an electric
motor to this . Via the clutch the engine can be disengaged and the
boat can be operated from the electic motor or close the clutch
and diesel driving the prop, the motor acting as a generator and
recharge the battery. So less components , so smaller and
cheaper system and most of the components can be smaller.
The electic motor needs to povide full power.
Q: Can you run both motor and engine at the same time?
Yes. you can run as electric only, or diesel only , diesel
with the motor acting as a generator. What we've done, during
acceleration the electric motor is helping the diesel ,
reducing emissions, it sdoesn't really reduce fuel
consumption. The emissions are reduced because the diesel is working
harder. There are also othe reffects. So can do both and add a
generator and you can do more. Most bigger boats already
have a generator, often 2. The generators ar eusually inefficient ,
put on one lamp and the generator has to fully run. Thee it would be
much more efficient to use a battery for that situatin.
So a hybrid generator. You can do mor eon boats than on cars.
The Venice taxi isa planing craft , when goinf fast
a lot of it is coming out of the water, with lower friction.
You can see that in the fuel consumption . Generally a boat is
low efficiency at low speed but this boat , when it starts
planing its quite efficient for a while, till wind resistance and
efficiency drops again. So optimum is probably when just planing
and so reasonable speed but most efficient. Its a bit doubtful
about fuel savngs but there are other benefits of a hybrid.
Reductionof local polution for example , which is pretty
bad in Venice. There is less vibration and low noise from an
electic motor. We tried to create a drop-in hybrid , so can
be retrofitd to old boats. Boats can be quite old, the ferry is from 1934
and the Venice taxi 1982. Just the engine tends to be replaced and on the
next refit , could include a hybrid, thats the idea. Also as the
engine is not running so much , less wear and less maintainence
so longer life a nd a saving there. The engine would be operating at a better
operating point on the curve. Electric propulsion allows you to go
very slowly , so manoeverability goes up. eg going in and out of a lock
they have to continally put in and out of gear , a lot of
clonking going on. Don't need to do that with electric because a motor
can turn very slowly. So much smoother operation .
We had to tart up the boats as they are both old, as part of using them
as test-beds, what are any potential issues and benefits. People underestimate
what is involved. They see all these components are easily available
, so surely it should be easy to put that lot together , but its not easy.
But control systems are not really available off the shelf, a lot of the
money goes into developing software. Imagine you're an operator
of 30 ferries and you want to make them more fuel efficient.
You would want to know how much you will save, what othe rbenefits
and what is the best system . This complete aspect does not exist at the moment.
Systems integration is the name. Before someone commits themselves to buying
an expensive system . The hybrid system is about 3 tmes more expensive than
#a normal diesel only system . Wil la certain system be reliable , which
gives the best results, cost-benefits, what other options are there, can I
use this for PR for instance. Will it consume more fuel . Take a hybrid
car used on a motorway most of the time it will consume more fuel than a diesel
only car. Unfortunately there is a lot of green-wash around this.
Someone suggested to me that I should be selling just the product sticker,
rather sad. Our system we try to make it as simple to install
as possible. Its very short, for the taxi stern drive and no space in the engine
bay, so we have to make our bit small to fit in what space there is.
Clutch and electric motor can do 40KW and the battery is under a
bench. So it takes up no space that would be used by passengers or their
luggage. I think we're the only ones can do this at the moment.
So system consits of the control, high voltage Li-ion battery and its control
unit and clutch+electric motor and lots of cables. Its important that the
interface for the driver has no change, so no confusion introduced.
The only change is a little display , tucked away, that can be used to change
modes. We've used the taxi around Soton for testing and demoing
and we now have to upgrade it to the system on the ferry.
Then take it to Venice, find an investor and supply ?? because the hybrid
system is new tech and we cannot provide world-wide support.
About 2,000 boats in Venice wiith the same drive system and about
20,000 more that are slightly different.
The next presentation relates the results on the ferry, the fuel consumption etc?
Q: What voltage cells are you using?
380V which is more or less what electric cars are using, so we can tap
into the same sort of components.
Q: The taxi , is that the original engine or did you change the engine ?
It would work with almost any othe rengine , but we bought the taxi boat without
an engine and got a new engine for it. The ferry had a very old engine ,
maybe 50 years old. With an old engine we cannot electronically control.
Q: Does stop and start cause a problem.? The taxi starts from the
airport and then its off for 10 minutes , not like the stop/start of a car?
Modern engines can cope better with stop/start, not so much heat mass?
so designed for start/stop. Also allows electronic control of the engine becaus ewe
cannot be utilising mechanical levers. Old engines tend to be dirtier, but we
prefer to go with relatively clean engines.
Q: So the offer would be new engine and battery for a taxi driver, because they
would be in the market because of a worn out engine? The whole thing in one go as part of
normal investment point.?
Yes, In venice these engines tend to last only 3 or 4 years. The cost of retrofitting
a hybrid system to an existing system and running for 2 more years is not
viable, maybe possible in the future.
Q: How long does the new system last com[ared to the existing types?
For the ferry project in Falmouth ,about twice as long, because half the
time it will be on electric. For Venice taxi boats , it would be more as they
are running on diesel a lot, very slowly . The ferry is going rapidly back and forth.
I even had doubts whether hybrid would make any sense , for such ferries, but it does seem to
make sense.
Q: Scaling up?. Is this just the beginning, can you scale up to quite
large vessels?
I think large vessels are possible. We've been here before. There's not much
market yet but a lot of competition already. Because on a world-wide scale
there are lots of companies and investors who think this has potential.
So we had to look at what is potentially our little niche. There are big
companies doing big ships.
Q: Did you study the Isle of Wight ferries at all. THe 2 big companies
are both saying they are green and hybrid , but don't seem to be in
port long enough to have any payback, I'm confused by this.
Hybrid in the sense that that is what is painted on the side,?
I think it makes not much sense. You can enter the port on both
sides in electric mode , for less emissions , but otherwise
pretty constant operation .
Q: In Corsica this year, tourist boats with 20-30 people on them
, left the harbour with no sound . THe PR value of this was
fantastic . It went into various caves then up comes the
diesel for the main crossing. A delightful experience.?
That is what we were hoping for on the Falmouth ferry.
But the engine is quite loud and an old boat so a lot of
vibration.
Q: Compaired with a car , the dead weight of a non-planing
boat would not matter, but what about the planing taxi?
Put it at the rear and it would plane all the time. Having a
battery , and its potential variation of placement , helps t balance the
boat better.
Q: A benefit for leisure craft , if you want to slip in or out
of port at night and not disturb people , that would be delightful,
at the moment we are shouting crew commands over a noisy diesel?
On the Falmouth ferry they do alot of commentaries and previously they
had to slow down at those times because the diesel was so noisy.
Q: There's lots of marine engineers familiar with diesel engines
but what about the electic side of hybrids , a problem of finding engineers
capable in that area for maintainence and repair?
Cumin-Raye? engines are not common at all, we have an issue with that
engine and no one can fix it.
For the fast section Venice taxis are there any hydrofoil hulls?
Not yet, some ideas around hydrofoils and different hull shapes
but at the moment they are pretty conservative. People like the looks of
their existing boats and it will be difficult to change .
Q: It strikes me it can be a minor alteration but a large power advantabe.?
The water buses in Venice are crazy old technology , the marine industry
does not seem ot be fast on the uptake. We have worked in racing , but that is very different.
The Falmouth ferry project.
The official launch was may this year and operational in July.
This ferry has operated between St Maurs and Trellisik in Flmouth.
Its a new route because they did not want to put this piece of innovative new tech
on a very important route . They thought this route, no one is going to use it
anyway. On the first trip we had 35 on board and 160 people transported
on the first day, which was a surprise how well the route was received.
Trellisik is National Trust gardens , a very nice area, and the reason for
making it hybrid. The river is noce and green and people want to
watch the birds and fish , so switching to electic in those areas is much less
noise and no fumes. Its an open boat , during a nice sunny day its
very busy in the open part and no one under the canopy part.
When a diesel boat comes alongside or leave the pontoon ,
they have to reverse, or the wind may blow from the stern and the
passengers are sitting in diesel fumes, not nice. With electric ,
no problem of that.
THe boat itself is called Kingsly 2 ? , its on the historic ship
register and built in 1934. It can carry 50 and up to 60.
We managed to get MCA approval for a hybrid boat , Lloyds register has
endorsed the battery system . Its 50 foot long, longer than the taxi boat.
So what is the fuel saving. The fery leaves St Moors ,goes to Trellisik and
returns, the speed variation is pretty small. It has to come alongside and has to
wait . It may have to slow down in the river going past moorings ,
and other manoevering. But what about any fuel savings.
The engine is directly connected to the gearbox and the prop. In between is
the clutch and a motor that can work as a mtor or as a generator to
charge the battery. ??? . The boat has much mor espace than the taxi ,
the battery is aft of the engine , best for weight distributuon.
There is a dc-dc converter for in the electric mode to charge 12V batteries for the
radios and lights. Otherwise much the same as the taxi boat. The motor is
40KW but only weighs 11Kg. We use the same batteries as Mitsubishi
plug-in car hybrid, of Japanese manufacture Lithium Manganese cell
type which is safer than laptop or mobile types. If it burnt it cannot
release its own oxygen, so you can extinguish it. Compared to cells based
on cobalt which can release oxygen when burning and impossible to extinguish
such fires. Its a little heavier but no matter on a boat.
The voltage is between 290 and 430 volts, 18.3KWh , thats always a lie,
from all manufacturers as it depends on how you use it. You should never
fully use it. You could fully use it but it would probably get too warm
during an 8 hour day of operation of charging/discharging repeatedly.
Q: Would Lithium-ion phosphate be a contender?
Yes but it has other disadvantages , its difficult to determine th state of
charge in a hybrid , because the voltage does not depend reliably on the
state of charge. Most phosphate ones are coming from China and manganese or
cobalt from Japan. So there are commercial disadvantages of dealing
with Chinese and Korean suppliers compared to Japan.
They are also difficult to balance, becasue of the voltage/state of charge problem
as you think they are the same state of charge but they're not.
Q: I bought a leisure one for my motor home , it works very well
but it does seem to loose track of what its doing and needs resetting,
probably what your saying?
Yes, they have some issues. I'm nit sure whether cooling is easy
with them either. Our decision was more based on having known them for years
and hoping to make a business case and working with the Chinese was never going
to happen.
These are automotive cells , so have received a lot of safety testing, which is
important for insurance and Lloyds Register approval. The Chinese say they cannot
send any certification. Same with Korean batteries, we cannot transport Korean
batteries any more because of dodgey certifications found out by a UK
transportation body. 3 independent test results looked suspiciously the same .
All this sort f activity puts lithium batteries as a whole into a bad reputation.
Its a safe battery , liquid cooled . For leisure boats , used twice a
year but a ferry is used a lot. Put this sort of tech on a leisure boat
it can be made cheaply as it doesn't have to last that long.
Q: I have a Nissan Leaf and its surprising how much the capacity
changes with temperature. Basically the hotter the better ,
then you run up against being a danger above a certain temp. Wht sort
of policy do you have. Also can you charge it up at low temperature
, then the temp goes up , without charging and you get more out of it or
charge it while its hot, I've no idea, a lot of info is just not provided
to the owner of such batteries. ?
Yes, all interesting topics and as usual it all depends. One great advantage of
this type of battery is you can charge it at sub-zero. Whereas all
the others normally theu say don't.
Q: If you charge sub-zero and warm it up , do you get more out of the
battery without charging it any more?
No, its just that chemical reactions work better at higher temps. Yo're getting
mor eenergy but you don't necessarily get more capacity, because the voltage
drop is lower . The over-voltage you need to drive the chemical reaction
can be smaller at higher temps but the aging accelerates, that the problem.
You want to keep it between 20 and 40 degree C , above 40 and aging
accelerates pretty fast. At 60 they will perform really well , in racing they
operate at 85 or 90 which is where you get most power out but they
won't last very long.
Q: Is the cooling internal or external to the battery case? and is that something
your control system takes care of?
Liquid cooling with inlet and outlet, 2 batteries split into 2, so for smaller
boats we can nicely position them. Its not salt-water cooling , there is a
heat exchanger for running the salt-water through there. We are actually
changing that, on the next Venice water taxi we will use sea-water
cooling for the batteries.
Q: For the batteries in theory you could use all sorts of electrolytes , I was wondering about
using salt water and the boat being one of the electrodes, and the other one being
something dangling in the water. Are you having to use Li-ion because
everybody does and therefore the most developed , because your not that
weight sensitive, so there must be other technologies possible. Just thinking
you're floating around in an electrolyte , why not use it? a daft question?
Generally the marine industry is not apt to change . The MCA is familiar
with lead-acid batteries on boats but put a Li-ion battery on board
and they only developed some rules a year ago for that. We had to look
at the system and writ ea long letter saying about safety etc.
I suspect you stating the use of lithium because everyone uses it is probably correct.
For a number of reasons , firstly people know how it works , know whats
available , no patent issues , more than 1 supplier is very important.
Another battery technology had one suplier who sat on it
and its patent but people want 2 or more sources. So there is some competition
and people can't fool around with pricing , you want a replacement, that will
cost you 5 times as much.
Sony? was invented by EA Technology ? near Oxford mainly for space applications
and Sony could see opportunity in this and were the first to put it in mobile phones
I think.
Q: It seems extremely narrow that society should just take a Walkman
battery and use it for powering cars , it seems amazing that no one has broadened it out?
We used lead-acid batteries for a very long time , NiCad came in,
that was replaced by NiMH . Lithium is not replacing Lead-acid so
much .
If its a cold rough-sea day and a battery dies , you would be in trouble, wheras a car in that situation can just coast to a stop on the side of the road?
For the automotive industry, they can try 4 or 5 types, spend a fortune on
engineering and validation programmes. The marine industry they don't.
They rely on replication of where its been done before and somewhere else.
Q:Sea-water sloshing over the batteries and extra electronics?
Just the air is pretty corrossive.
Q: But you do have 2 mechansms for powering as long as they work when
one packs up, is better than just having one power source. ?
We've used that redundency a few times , both ways. In Soton we had the diesel
of the taxi pack up just in front o the fast ferry. So I was glad we had an electric
motor that could take us out of the way.
On the ferry we implemented a backup, for the crew. There is a lot
of software , so no longer a hammer and spanner will work . You have to
have 5 laptops and 3 ? at least. So they were all afraid of this complexity.
So its a matter of changing a few relays and its back to their old diesel
only, the whole hybrid structure is disconnected, is a feature that
people like. For the ferry we've over-sized the engine, sounds a bit
counter-intuitive. At one point on the operation curve we need
60hp but we went for 200 hp engine instead and we changed the prop
and gear ratio so the prop thrust curve has changed , overloading
its sometimes called. When you put the gear in , the engine is
ticking over , its not a smooth clutch , so clunk. But as we've overloaded
it , its too much for the engine during an emergency stop and it
stalls. So we've told the electric motor to help it so
it doesn't stop. If it was not a hybrid you could not do this,
another way to make it more efficient.
So you have a fuel powered engine in your boat so
you are already paying for friction in the engine as overheads.
Can you now add the generator and take energy out for battery
charging - how efficient is that because your already paying for the
overheads. So this curve shows this horizontally speed in knots
and vertical axis the engine efficiency. At low speed the engine
is inefficient and becones more efficient as speed goes up.
The top efficency is about 37% for the diesel engine ,
but now add in the generator then we are pushing the engine into a
more efficient region. That means the elctric energy is generated with
an efficency of 35 to 45% from the already running diesel engine ,
which is pretty good.
Q: Do any of your rojects rely on external ?ing?
Its not a plug-in hybrid, its self-contained. Normally thats a
disadvantage because there are just no recharging points on the Falmouth
run.
Q: With that efficency increase are you getting something for nothing?
Not for nothing but you get it pretty cheap , much more cheaply than
running a generator. If your boat needs a generator anyway, diesel
propulsion and a generator it would be better to use the diesel
just for propulsion , than the battery-hybrid system with no generator.
That sort of system exista for sailing boats now. Thats a pretty clever
system especially for larger sailing boats. People have a diesel then
a generator and they don't then need a generator any more.
So the marine market is more diverse and interesting when it
comes to electic propulsion , than automotive as so many different
aspects to consider. The ferry performance, x-axis speed in knots
v the power required to push that boat at that speed.
So if you do 2 knots you need next to nothing like 1KW but goto
4 or 5 knots, the speed limit on the Test and Itchen is 6 knots, you
need 10 kW for a boat carrying 60 people. So a boat is pretty
efficient at low speed. But a diesel cannot operate a boat slower than
this , improves at higher speed where the boat gets worse.
So what overall efficiency. We had a number of laptops logging the
results on a rainy day in Falmouth. The fuel consumption in terms of
equivalent litres per nautical mile.
x-axis vessel speed i nknots , one curve shows the fuel consumption
the boat could have theretically if the propulsion system was 100%
efficient. A propellor good be improved but take it as a boat from
1934. One curve is the fuel consumption if it was purely electric,
pretty close to being optimum. The other curve is diesel only and quite
bad in comparison, because diesel is not very efficient.
The boat is good at one point on the curves but the diesel is bad,
and elsewhere the boat is bad but the diesel is good , so
no obvious sweet spot. But if you have a strong tide , things change
though. The hybrid curve, difference between diesel and the electric
, I cannot go electric all the time and have to recharge and so using fuel.
I'm using more fuel than if I was not charging , so I don't get that
for free , just cheaper . When we go to diesel we will be pretty fast.
The curves show it makes sense up to 7.5 kn it makes sense to go electric
because you're consuming less fuel. One question when demonstrating the
boats is , whats the range. It depends a lot on the speed as the boat is very
efficient at low speed. Go at 3.5kn you can go 12 nm with the ferry
in electric mode. But if you want to go fast 7.5kn then only 3 nm.
How fast does it recharge. Running on diesel at 6kn it takes about
8nm torecharge and go at 10 kn its much the same. Little difference on
what speed you do in diesel mode, dependent on the setting of the boat though.
Its about 30 minutes about 15 min on electric and 15min on diesel.
Going slow is always electric as is manoevering alongside , very slow ,
so disproportionate amount of time , where the diesel is pretty bad for this.
So the fuel saving of combined compared to the same system running
just on diesel.
Go slowly in electric mode about 20% saving , go quite fast and the
saving is only 5%. If you go too fast in electric mode you start to require
more fuel. This does not take into account ,in normal operation ,they
often leave the engine running . It also does not take into account
the ability to overload the engine , there are othe rsavings.
Skippers are now a lot more interested in all this , asking about
fuel saving possibilities as well as how to save the planet, which they
didn't do before. So that is the worst case in terms of fuel saving because that
ferry is not the most amenable to such fuel saving as its just going back and forth.
Venice taxi boats would be saving more than that .
Q:If you could do the whole route under solar panels, would it
make a negligible contribution or some contribution?
I think it would make quite a good contribution because , 2 to 3KW with
panels on the cabin top. Something you'd have to worry about
is spray on the panels. If not marine quality there would be galloping
corrossion and salt deposits , so a bad environment for PV panels.
Q: At either end of the route , is there any shore power?
None .
With appropriate PV panels and daily surface cleaning and assume 3KW
that boat can do about 4.5kn so noticeable. Also its only operating
during the summer.
People don't seem to use the term Lt/nm , they use the term Lt/hr
a lot in marine matters because they use that for calculating
range and fuel requirements. So its pretty hard work to save just that
20%. If people reduced their spped from 9 to 8 knots they would
also save 20% . Much easier to do that . Perhaps they could improve the
hull , use a different prop or just clean the prop and the hull , much
easier perhaps in terms of fuel saving. But a hybrid system does have othe r
benefits.
Q: less stress on the diesel engine and maybe extent maintainence intervals?
Yes
Q: You could be bringing the world of smart meters into the marine world.
Providing something for skippers to aim for.?
Non technical aspects of this should not be under-estimated. With hybrids
and so electrification it enables a lot of other things. It enables solar,
shore-power , cappoccino machine on board and other life benefits.
So the question asked, why should we change propulsion system to hybrid
and just save 20%, does it really matter. Its not just the fuel saving , but all
the other that comes with it, looking for different fuels which could be methanol
or hydrogen for example . Electricity all very nice but hybrid for the range.
Some applications , purely electric would make sense. Other applications
series hybrid or fuel-cell hybrid makes sense. Some applications a hybrid
makes no sense and I'd say don't by hybrid. We had this where someone in Canada was operating 20 boats in a nature reserve and he was keen to buy our dream hybrid
system. But the way he operated the boats he'd use more fuel .
Q: Is the ferry a "Little Ship" one of the fleet of WW2 Dunkirk evacuee ships, they used a lot of boats like that ferry, right age?
This one came from the Scilly Isles and always on Scilly .
Do you see any inerest in having mainly electric but sort of limp-home
diesel that won't give your normal cruising speed but would get you home
eventually, with failed battery capacity? Often big boats with a big engine have a small one for if the big one breaks down?
Peace-of-mind , yes .
I went to a marine talk and someone in Holland had installed hybrid in tugs,
any thoughts on that?
Daemon? has made a few. I know they had asn issue as they gave skippers the
option of using the hybrid or the diesel and given the choice they were familiar
with diesel and switched off the hybrid.
Our ferry skippers are more the other way, keen to go electric, but they
go a bit too fast on electric for my liking .
A featur efor electric cars is supposed to be superb acceleration, is there a
marine equivalent?
Yes, it really related to manoevering where you have instant response.
You could have bow thrusters electric as well.
A lot of motor-boats have 2 engines anyway, one port and one
starboard. With your system could you have one electric and one diesel ?
Possibly, they'd have to be matched in all performance modes .
Whats the function of variable pitch props ?
I'm not a prop expert , I'm told you can easily save fuel by having
variable pitch props , similar to all this hybrid stuff but you'd not
be able to improve your emissions. On emissions there is argument
as to whether to install a big and expensive scrubber on a boat,
or install a hybrid , but no one seems to have done comparisons.
If you had shore-power then presumably it could be scrubbed further
up the line?
Yes, that comes up a lot. It depends what sort of electricity you buy or
use. Most people who drive electric cars would buy green electricity
from wind+solar or their own solar PV. There is similar issues
with recycling schemes. If no one puts glass into recycling then #
recycling makes no sense. Thinks don't happen nicely synchronised.
We have to clean up our grid and it should all be CO2-free eventually.
At the same time using more electricity. Electricity is the easiest
form of energy we can create from renewable resources.
Liquid fuels have the great advantage of high energy density
but its difficult to produce sustainably, like
methanol from CO2. But if you produce it from CO2,
you're just delaying the release of CO2. At least you
use it twice, so not so bad in that sense.
On speed controls, I recall boats being banged into and out of gear
for minimum speed. But hybrid allows nice precise speed control
on electric. Would skippers accept that? Do you have a sort
of exponential throttle , to take advantage ofthat preciese control at lower speeds?
Yes we have a control that is not linear, so they get more control at
low RPM and also at high RPM.
Q: Do you get unsolicited positive feedback on that?
We went through control system changes in developement with a skipper
settling on what was quite nice and disliking other settings.
On this ferry the gearbox cannot operate at low RPM , so it still
has to be banged into gear. But they are developing hybrid -
ready gearboxes which are supposed to be finessed. Its hydraulic clutch control
and the hydraulic pump is driven off the shaft which has to
rotate at a certain rpm or the hydraulics don't work so then the clutch
doesn't work.
You've only got a small sample of uses, 2 boats and a few skippers .
Comparing with electric cars , so many other benefits , no usage stuck in traffic
and other things coming out, a completely different mind-set. You've
not yet been able to cultivate those present unknowns in your audience. ?
We've used questionaires amonst the ferry passengers and thatgiven us some
answers on thinking. The ferry company has a number of skippers , not just 2.
The Venice boat will go to Venice and be shown to as many people as possible.
Irs got to get to the satage where a skipper will buy a hybrid
system because of all the other features he was not aware of previously?
A trouble with the commercial market is the 2 layers, who is your
cutomer , is the passenger or the purchaser . Especially the Venice boat we have
to show to the local council what is possible. Because only then
canthey produce the restrictions for diesel use, at the moment there is no
demand, the demand has to be created. This is a general problem with
sustainability. In general there is no demand , the tech vto fulfil a demand
is there . Killing the planet , new tech developement , but who is
asking for this tech.
I was involved with the developemnet of the first colour IT display
and we deliberated over how many will we sell , as a prestige item
costing 4 times as much as the existing green-screens. So a room of
200 users, but give one to the supervisor as a hierarchical thing.
We thought the market would stand 85,000 , but once they started
getting out there, no one wanted a green-screen. Our customers
buying these , could not recruit staff unless they changed ovver to
colour ones. You only use monochrme these days to signify stuff thats
out of date?
I bought the first battery car in 1998 and loved it, and thought why
is no one else buying these. We were the first in Europe to try
Li-ion batteries in electric cars and hybrids and there was some interest
from the press but no interest from investors then, because they would ask
how big is the market, how many can we sell . Then Elon Musk
believed in it , used his own money, and the rest is history. That is the sad
thing people don't believe in something . The Chinese are believing in this
and they are investing .
For a replacement technology you need a disruptor like Musk?
At the moment people are more reluctant tobuy diesell and hoping electric car
prices will come down ?
A chicken and egg problem with e-cars, they get their ecar ready
Mitsubishi and GM not selling well and the CEO is in trouble.
Something that has worked is Formule-e racing?
In the states with Tesla they go mountain racing at weekends, get to top and then
on the way back regenerative recharging for the braking .
Tuesday 17 September 2019 Malc Pearson Action on Hearing Loss volunteer, talk on hearing loss.
We have support groups in Soton
We have lots of small groups with us, we have training and I'm part of that.
We give training, mainly to corporates , for diversity and deaf-awareness.
We have campaigns, we lobby . We were very active lobbying for subtitling
on TV. We do research , including at Soton uni
on likes of cochlea implants and tinnitus . We also sell eqipment, there is so much stuff
to support you when you are deaf.
Firstly can you hear my voice, because I can't hear my own voice.
Sometimes I shout, sometimes I go quiet, sometimes it goes off pitch,
give me a nudge if I do .
For people who are totally deaf, right thru to the other end of the
spectrum with mild hearing loss , 1 in 6 people.
11 million people in 2018. It goes up in over 35s to 15.6% because its in the
older generation . We're living longer , therefore more people with
hearing loss in the future.
Profoundly deaf, probably sign-language users or lip-readers.
Sign-readers 24,000 but its not taken up by youngsters. Wefind sign language is a
very efficient language. But you need 2 people to tango, if you sign you need someone
on the oteher side to receive signing. So when you interface with an
employer or the general public, there is a problem.
6.7million could benefit from a hearing aid HA , the NHS say they've issued about
2 million, so a lot of people out there who could benefit from a
HA or two.
How to you individually recognise deafness, discuss with your neighbours
for 3 minutes. Deafness is invisible, look at me and how did you know I
was deaf.
I might tell you, I did tonight but normally I would not, if I
met you on the street. If I do then you start to behave very peculiarly.
You start to give me very strange mouth patterns. I need normal
speech to be able to read it, not emphasised. People tend to
react and over-react. So I shuffle along a bit, perhaps flash my
hearing aids at them and slowly go into it.
I have 2 HAs, 2 NHS ones and with short hair they are
very visible, I quite like that as it helps me tell people that I'm deaf.
ts fashionable now to have things stuffed in your ears. It used to be
that people did not want to be seen with things in their ears, not any more.
I don't respond if people talk behind me. I do hear bass notes ,
so something dropped with a loud bass note, I'll hear that.
So people walking along a footpath who want to overtake and say something to
me , i don't get it. My vision is what I hear.
When you're deaf you observe things in a different way. You get glances from
people walking past me , because they've said something, and I've not
picked it up.
The different voice. I've been hearing for most of my life , therefore my
voice is reasonable. Now I don't hear it properly I usually shout .
Usually people who ar edeaf have a different kind of voice.
A colleague of mine who gives talks has never heard her own voice,
has to modulate it by touching her throat to gauge the volume.
Once set for the day , she's usually alright.
Go somewhere and the TV is very loud , they probably have hearing loss.
Similar with loud volume in a car, could be the fshion or compensating
for lack of hearing.
Lip-reading. I only get about half of lip reading content, I have to make the
rest of it up as I go along. SoI get it wrong very often ,misunderstanding
things. If I go wrong like that I can tell from people's eyes that I've
gone wrong, we have to back-up a bit and restart.
As a lipreader, I don't have eye contact, I look a little lower.
I'm actually looking at your teeth and you tongue , so that sort of focus
is slightly off and that does worry people. They get a bit uncomfortable becaus eI'm
not giving them pure eye contact. It can get a bit embarassing at
times, when I'm tired I beging to stare. If I don't know th eperson
and they don't realise what I'm doing , its a bit unnerving for them. But I'm aware of this and have to compensate. So if someone seems to be staring at your lips they're
probably deaf and are lip reading.
As you get older, bits wear out .
I can't go to dinner parties becasue when people are eating and drinking
and also talking , it all goes completely out the window. Equally any
social interaction where you have to interact with people , lots of
people trying to talk to me, it gets very difficult.
I only go out to dinner with people who know me and they can compensate
and help me thru it. If someone is withdrawing from you in a social
situation deafness could be the reason why.
If you want to learn something different , sign-language. It makes you lok
at languages in a very different way. But you need 2 to tango , so you don't usually
see it in action unless 2 people are deaf together or going to a club where
they know deaf people will be present. Some deaf clubs, sign language is the
only langueage that is used inside those clubs. So a place of silence, and if
you tried anything else in there you'd get some very strange looks.
The red and white stick, that means visual impairment and hearing
impairment. Not a barbers pole but red/white/red/white, they won't see
you very well and wont hear you very well. So you have to think about
how you will communicte with them. A light touch on the shoulder and then
move in front of them and then let them drive it, as they know what to
do. They will guide you from then on. If its an emergency , say someone is
stepping into a road, grab them by the arm, if an adult.
Q: I've never seen a red and white stick, I'd immediately associeate
it with a surveyor's staff. Would those poles have one of the
sounding lumps on the end,for echo gauging purposes , looking like a golfing stick?
Yes
I've seen the plain white but not red and white around?
They are around Soton.
Q: I've a problem understanding women rather than men, because of
upper frequency sound loss. So if you find male voices easier to understand than
female , that can be a signature of deafness?
It is , when I show you the innards of the ear , you'll see why that happens.
There are 2 big reasons why you can go deaf. I'm not a medic .
Conductive deafness , where you hear everything but at a lower level,
just as turning the volume down of a tv. You hear everything but have to
strain to hear it. The second is perceptive loss, where you've lost a
band of frequencies . Usually that frequency is in the higher band,
but it can be anywhere. My loss was due to an illness and it caused me to
loose several bands going along the route of the cochlea.
This gives you distortion of the heard sound. As you get older you get a mixture
of both. I started off with the second but with age then the first as well.
Ear flaps are designed to catch the moving air. It sticks out and funnels
the moving air down the ear canal to the ear drum. This is a living
membrane that goes across the ear. Inside of that there are 3 small
bones , the smallest bones in the human. The first touches the back of the
ear drum , picks up the vibrations that are now physical
movement and passes thru the next 2 to the end of the cochlea.
Its like that because it needs to move , because your jaw
moves and your whole head moves so it has to be a flexible joint.
As you get older your bones change , these bones change as well
and they're not so conductive , therefore its like turning the volume down.
The transmission of vibrations across that bridge are not as efficient as they
used to be.
The cochlea, thumbnail size and snail shape. Its a hollow tube, 2 tubes
in fact. The centre of the tube is fluid filled . If I straighten out the snail
shape , a tapered tube. Inside the tube are thousands of hairs ,
pointing inwards that pick up the vibrations. At the hair ends are
nerves , which all join together and become the auditory nerve tha t
send electrical impulses toyour brain . Responds best to high frequencies
at the narrow end and bass frequencies at the wide end. All the vibrations
start with most amplitude at one end , takes a lot of work , because all the
vibrations have to pass through those hairs, you loose those, they wear out
and they won't replace. Thats why you start to hear mens voices
better than women's. The illness I had, got into the fluid of the ear
and it destroyed the hairs in some patches, so I've lost those
frequencies. They can't be replaced, nothing you can do about it.
This is all vibrstions that the hairs pick up , converted by the
nerves into electricity and the brain does all the work of converting into the
sensation of hearing, same with eyes.
Why is one tube larger than the other?
Just a schematic , the main tube is what I,m describing here. There is a
second tube that picks up secondary waves , and the brain compares the two, so
more complex than what I was saying. For the purpose of understanding ,
just considering one.
What s the normal hearing frequency range of ordinary people?
About 20 hertz to 20 Kilohertz, only for very young people, it drops off
quite quickly as you get older.
So the communication needs of different people. If you're a hearing aid
user , you need signs and subtitles as we are using our eyes as well as
the small bit of hearing we have got.
If we're lip-readers , we need note-takers and speech-to-text to
help us. Note-takers are professional peole who will come with me to
a uni lecture , because I can't look at a lecture and write notes at the
same time. Speech-to-text where someone with a special keyboard
would type in what is said and it would come up[ as large font print
on a screen. You see this in courts where there are people with
hearing loss involved. There are signer-readers and interpreters,
people who will sit between and a hearing and a deaf person who
is using sign langauge. You can engage such people by booking thru
the charity Action on Hearing loss. With an interpreter its very eady to
end up talking to the interpreter and not the real interviewer.
Aubtitling , I use it all the time. It started with BBC doing some programs
and now its across most of the companies. Usually subtitling is pre-recorded
bu tsomething live like the 10 o'clock news , they don't know what they will say until
being on air. You can tell the difference, because it comes up in blocks
and often a wrong word in there or mixed up . The software they use protects from
strange words coming up .
Q: I noticed on BBC reletext this week that they're stopping the red button business.
I've always liked that facility , compact concise precissed text and if anything
piques my interest I look on the internet for it, armed now with a few keywords. Snippets of news in that
structured /teletext/ceefax way I'd have thought was very useful for a deaf person?
Its wonderful for us as an information source and as a communication source.
Q: Is that text-biased news/weather etc very useful to the deaf in the same manner as
subtitling?
It is important to us. I've not heard any comments , no lobbying that I've
seen about the red button , its only just come up in the news, early days.
We've had a long campaign to support subtitling ampng the various
companies . When we have a problem reported to us we go and try to
sort it out. A problem with subtitling is its often imported films
, which is inadrqute, they need to put it on for an English voice.
Everybody lipreads to some degree. Have a conversation with a
friend and put a hand in front of your mouth and I guarrentee that your
friend a few minurtes later will ask you to move your hand.
Its also reassuring to see the lips as people get the emotions
along with the speech. If the conversation
is going well , it flows well, a nice smile on your face, a warm look
that people acknowledge. Lip-reading isn't just about the lips,
its the whole image of the face.
Lip-reading needs a lot of concentration, I can only lip-read
for about 30 minutes , after that I've lost it, I have to go outside.
All a bit strange as I do most of the talking , so lip-reading
can be a challenge to do at the same time.
I get to a point where things become jumbled and I go out and have a coffee,
unfortunately the peole come with me. I just want to go away and have
some time on my own for a few minutes. About 50% accurate.
Its a bit like predictive text, people say things and you respond to things
in set patterns . When your close to someone you can almost tell what they will
say before they say it. A lot is inteliigent guess work, but that also
creates mistakes and you've got to acknowledge that.
I come wiht a kitbag and when you go to lip-reading clases , they tell
you to carry a kit bag with you. I'm happy to share some of my tricks with
you but not all of them. The first one is I start conversations, you
don't stand a chance of starting a conversation with me, because I will
start. When I meet you ,I'm in there . Then I know what we're
talking about. If i let you start , I'd have not idea what the
topic is, it could be M£ traffic, a sunny day or whatever. If I start , it
lets me relax and it lets me know what we're talking about.
Some people think I'm pushy because of that, but hey, thats the way it works.
We have thinking words and one of them is really!. If you say really to someone
it answers most things. So if I'm stuck, I say really and we can move on,
without shocking?. As soon as I shock?, then the funny mouths and all
the rest of it. I like people to speak a little slower than normal.
I can slow you down, by making my speech slower , you'll slow down.
Try this with someone in conversation. You need good lighting
, I can just about manage with the low level lights here for the projector.
Often the new downlighter LED lights in houses now are terrible because
your nose shades your lips. Often people are standing under one of those
strong lights and I can't see a thing. I move to the
side and the other person moves with me. I don't have ot say , lets move,
they come with me without explanation. We do come out of lipreading
training with a load of tricks.
As a demo of confusing groups say amongst yourselves as pairs while looking at
each other.
Say ma (as in murder), be ( as in Bert) , pe (as in pearl).
You should see they all look the same shape, known as confusion groups.
Most of you were smiling then, as soon as you smile , it distorts the lips so
you have to do this with a flat face.
Some more Che (as in church), Sha (Sherbert) and ga (as in gerbil)
you can feel your tongue going into different positions from the previous group.
The and Fe (as in fir) is tonge position.
Finally Ta (as in turban) and De (as in dirt) your tongue is behind
your top teeth and again your jaw shape is diffferent.
Its not just your lips , its your whole face shape, that changes.
If you say, tea on Saturday and dinner on sunday, look at how those
appear as lipreading, very close lips similarity, so easy confusion.
When you're communicating with someone with hearing loss, the image
your portraying becomes part of the language.
So drink a cup of tea with me look at my face appearance . Or driving
along a road in the country without a care in the world compared to
facial appearance when driving a bus in the rush hour.
How can you help with hearing loss. Find a quiet place, this room is
wonderful, lots of rooms have fans and other noises going on and
traffic noise coming into the room. So how would you get my
attention there. If I'm focused over my laptop say, bring your hand
into my vision from the side. A light touch on the shoulder , a heavy
touch if there isa fire. Face the person, a lot of people try to face the
person but end up half way, come all the weay round.
If you're going to talk for any length of time , try to include the
subject in your first sentence. Slightly slower than normal but try
to keep the normal rythm going. Going slower tends to exagerate the
features on your face around the lips. Take turns in talking,
if you talk over , it will all fall apart. If you shout at me
and I understand it , I'll shout back, other than that your face looks
angry. So if someone shouts I immediately see anger and therefore
I assume there is a danger.
Its quite panicking when you see someone you don't know shouting at you.
Don't waffle. When you study sign-langauge its amazing how many
words are unnecessary. Keep to plain language. Re-phrase something
if its not going well . If it gets to the time where I can't take any more,
pack it in and restart in half an hour. But please don't give up and walk
away. Worse comes to worse write down on a bit of paper.
If you walk away , I think he doesn't care and this errodes friendships.
I have a sheet here with communication points from both points of
view, hearing and hearing-loss.
You can check your own hearing by our health check ,
phone the number 0845 600 5555
and press the keypad for different tones for about 10 minutes
and use a landline phone not a mobile . It will say your ok
or need to have it checked . Also repeat again for the other ear.
NHS service are via your GP or you can go the private route.
Learn to lip-read, quite a few free tutorialsd on the internet.
There are some on our websirte as well but if you ant to do it
seriously , you join a group, often attached to libraries,
so you go to a community, you just practise. There is a structure
to it but most of the time its quite social .
There's never been a better time to be deaf with all the tech
around. You could spend a fortune on it if you want.
Communicating text , there is Whatsapp, all these apps gives a deaf
person access to communication that was not possible
before. THe leaflets I brought along , do get out of
date very quickly , so go to the website where the pdf files
are updated . There are hundreds on there. Any sort of issue,
you'll find something about hearing loss there. We have an
email newsletter as well , once a month.
https://www.actiononhearingloss.org.uk
Q: A language spoken with a lot of sibilance is very difficult to
hear.
When you talk vto people who are not deaf , they do pick up
a lot from what we do not say. Particularly youngsters, I'll
be talking at the Solent uni on friday , they ar eso interested
on hearing loss because its such a common thying.
Q: I went to have my ears tested and he said a lot of people have
accelerated hearing loss because they have these things in their ears.
I'm told that when you're on a train you can hear the hedphones of
someone two people forward, buzzing around. That is so
dangerous - also the noise in a car.
Earlier when you all were discussing how you would recognise
deafness in someone, you registered 80 dB, via an app on my
phone. 95dB is the starting threshold for hearing damage.
That sort of damage is recoverable if you go somewhere quiet
afterwards, but do it continuously or for a long time, damage
will be done.
Could you saya bit about signlanguage. My daughter is teaching
my granddaughter a simplified sign langauge, macaton?
Often used in schools especialy children with spacial needs as well.
Is it a stripped-down Brittish one?
The language structur eis different. If you are asking what is my
name, it is structured name/me/malcolm. Word order is changed from
English and trivial words are just lopped off.
The important stuff comes first, incredibly basic like that.
Why is there no international Esperanto sign-language?
No one could agree. Not enough people because to develop
you must have someone to sign to. Lip-reading is very
common now. If you can look at signed TV program
you see the word order is completely different to what is being spoken.
For TV signing they use exagerated facial expression?
Yes, a lot of the separation is the face, different expressions have different
meanings.
I've heard they use male speakers for older viewers and then there was complaints
about gender equality .
Very true . There is AD audio description , like teletext but
describing the scene. Where this is done by a woman they choose someone
with a lower pitch of voice . But they also needed a voice that did not
clash with what was being spoken . Have a go with the AD button
on your TV controller, not available on every program.
The aspect of everyone can lipread to some extent. I used to know
someone with cerebral palsey and because of the distortion of his
speech , I found I dropped into a mode of looking away
from him and then I could understand him. If I looked at him, somehow
the distorted mouth-form distracted or confused my underestanding of his speech.?
It just shows that we all must have some background ability at
lip-reading , by this converse.
Its easy to have a hearing test, these days its almost automated.
It comes up with a graph that shows your hearing loss. Then they can
set up any HA to your needs.
W151
Tuesday 19 November 2019 Steve Page of Hampshire Bat group: Bats - How
do they do that? - I set out to describe how man’s curiosity to
discover how these often tiny creatures fly around in darkness and
catch their prey! Covering how man’s challenges to develop ‘stealth’
technologies also led us to unravel some of the bat’s secrets.
I was one evening watching a cock-chafer trying to climb a piece of
grass but ungainly. The sun had gone down and it made it up, opened
its carapace , opened its wings and buzzed off into the sky, I was so
impressed. A large bat came along and gobbled it up. My intro into
bats in the wild and I decided to find out more about them.
I found out it was a ceratin bat , reasonably conspicuous around
urban gardens. A nightime pic for a dark
skies event i nthe South Downs Park. In Cornwall with the orange glow of
streetlights over Scilly on the horizon . This is the bat's domain, just the
light of the Milky Way, no moon. We can just about stumble
around in starlight .
Inside Privett Tunnel , a disused railway tunnel in Hampshire near Privett,
left over from the Newbury line, built as a double track so a large tunnel.
We do a survey there twice every winter. The tunnel goes under the hill
at Bailey Green. S-shaped tunnel and very dark when you go in there,
once around the bend even if the door is partly open. It is pitch
black. Temperature is always about 8 to 10 deg, pic of a
max-min thermometer been hanging in there for decades and not been reset.
You're trying to find bats that get into gaps in the mortar between the bricks , countless thousands of bricks, 2km long tunnel.
Behind the brick lining there is a gap between the brick lining and the
chalk hill. So if there is a way thru , there is potential for a larg e
roost in that void. We still find significant numbers of
bats on the brickwork. When a bat is sighted the re-assembled throng try to
identify it. A tally and log is kept of the count.
A demo of taking a pic with a coupled camera and battery spotlight of a patch of
brickwork 20 foot away, of a bat sized blob in the mortar.
A typical overall view of a few square yards of brick with 3 bats there ,
but not to untrained eyes. They don't need much space , its often the case there
is one behind another squeezed i na gap. Asleep or semi-torpor.
Hopefully they stay that way after we've passed on .
Time of day is immaterial from such a survey, we usually do it on
a sunday morning. There are no light clues to any time of day.
But there is research that tells bats when it is dusk, some work done in
N Hampshire.
A Great Horseshoe bat , the first time one found in E Hants, for many
years. It decided to roost at the side of a BMX track by Knightly,
in 2007. 15 species of bat are d=resident in Hants, 17 or 18
in the whole of the UK.
The Nathusius Pipestrelle is an interesting one.
The Grey long-eared are fairly well distributed in Hants.
A maternity roost we are aware of in Ower we have some video of.
400 million years of bats evolving in their particular niche.
They've become used to the acoustic spectrum rather than the
electro-magnetic spectrum . The end of the 1700s scientists
started looking into them.
There is a strong element of bat science in Hants.
Bats are mammals and shares our skeleton structure. The main feature is the
wing web that joins up the fingers. The extended thumb is used for
gripping. The calthar joins rear of the hind leg to the tail.
Same number of fingers and joints as do we, but they've used them to
adapt as a flying aid. Bat manoeverability in the air compared to a
bird, is a bat flies by its fingers rather than its arms. We used to think
bats were crepucular , but we nw know they are nocturnal as well.
They've got good eyesight which they can use, but don't need to use.
The first to emerge before sunset wil lbe pipistrelles.
A bat can eat 5,000 midges in a night , which wins them some friends.
Very light as mammals go , about the weight of a 20p piece. Roughly the
size of a small shrew. A shrew has only the range of how far it
can run , bats can range over kilometres in search of food.
They make social calls when resting . The need their social calls
because they are blinded by spacing?.
In 1794 Italian priest Lazaro Sparazani? was curious about this so
he designed an experiment. Quite clever experiment and wrote it up
in a paper. He hung some bells in a room , completely
blacked out , introduced a bat and he heard no bells. He did varios
unspeakable things to the bats until they did crash into the suspended bells.
So something inherent to bats allowed them to navigate between
hazards, when the bat was intact. He decided there was some sensor in their
limbs that allowed them such navigation, not discovering eco-location
as such. 1794 was the year after Gilbert White of selborne had died,
so contempories. Jump to 1948 at Harvard Uni a graduate was working on
some defence contract. As a result of WW1 and the Uboat threat ,
they developed Sonar , pinging out noises and listening for echoes.
The combatants found out and started fitting listening devices to subs
to be aware of their presence. So the next endeavour was to determine a
silent way of doing this, ie using ultra-sound. So the first serious
work on ultrasonics , so ultrasonic sounders and microphones were developed.
Donald Griffin , whose work had been in bird migration , but an interest in
bats. Stil lthe ongoing mystery of how bats navigate without crashing into
things. Prof Hartridge of Cambrisge Uni postulated it may be something to
do with acoustics. Griffin obtained a bat and placed in front of
a suitable mic and they could see a trace on the oscilloscope.
The first scientific discovery of echo-location , which is
what griffin called it. In a paper at the time Griffin wrote this ,
a lot of scientific disbelief.
We hear 50 Hz to 15 or 20 KHz depending on your age. But sound goes
way up into the MHz. Uses for ultrasound in non-destructive testing
of engine components etc, medical uses . For bats we are interested in
20 to 100KHz ,higher for some bats but not in the UK.
Griffin was born in Southampton , New York and had a lab in
Millbrook, New York. Which is where we are going to next. In
1963 the first commercially developed bat detector was
developed in Southampton here, as a result of work by
Andrew Watson and some people at Sussex Uni. A defence
contractor in Totton , Holgate , produced the first portable
bat detecor and its here tonight. It looks a bit military
of the time. It is tunable , an output for an oscilloscope .
You can tune it as BFO beat frequency oscillator, it is
heterodyne . A volume control and an output to a tape machine.
In concept it was originally a long-wave radio , taking out the
aerial and put in a sensing circuit for ultrasound.
Ultrasound microphones were not commercially available at the time,
or perhaps not economically so. So they made their own , using
a diaphragm and some acorn/peanut valves. In the military
when they wer etrying to miniturise electronics , before semiconductors arrived
they made the valves as small as they could , the size of a torch bulb
with prongs sticking out. The meter of the time was an Avo 8 , large
bakelite box and large dial and used an expensive highish voltage battery
for high resistance ranges that
lasted a few years. This Holgate used 15 of them and probably would last
just 2 nights , so very expensive. It cost 98 pounds 10 shillings in
its day. My dad as as askilled compositor was on 14 pounds a week
at that time. But it was the first usable , portable bat detector
Andrew Watson led on this and bear in mind that at that
time there was litle interest in bats except a few academics.
Partly due to no protection to bats, so no career involving bats such as
regulators. So very fee of these detectors were made , but much sought
after by people of the day. A pic showing Watson demoing his
detector to the chairman of the Mammal Society, Lord Cranbrook
on his Suffolk Estate. I'd not be surprised if the bat detector in the
pic is the one here tonight. The other 2 people were holding the
big reel-to-reel tape recorder. At that stage all they could do was
listen to the tapes , other than perhaps some analysis via
analogue oscilloscopes, not much else at that time.
In 1975 the Protection of Wild Creatures and Wild Plants Act came in
and in 1981 the Wildlife and Countryside act came in which protected
bats. Now they were protected, they needed some tools
toensure that happened . Bat researchers were interested in availling themselves
of bat detectors, so quite opportune they were developed around that
time. After my encounter with a Serotine bat I made my own detector
and found a kit you could buy to make your own. It worked and it still
works , rattling a bunch of keys works quite wel. A bit chicken and egg,
as having made it and turned it on , I didn't know what I was listening to.
Nothin at the time to tell me. I sought out Hampshire Bat Group and they ran a
bat-detector workshop.
The next detector is a professional one , a Petterson goto one for
ecologists about 1000 GBP in its day , no built in recorder .
Works very well , very reliable, various outputs heterodyne and
other sorts of signals. The modern kit is an attachement for a
smart phone, a Wildlife Acoustics device. Its powered from its
host , using the screen of the phone or iPad and can record onto it.
These have elevated the amount of captured data , because you have in
your hands a piece of lab equipment. Very small, very light weight .
So easy to record , easy to distribute the recordings and to analyse them
in the available software. They are a few hundred pounds .
When if flight bats call loudly once every time they flap their
wings. A small bat with rapidly flapping wings emits lots of chirps.
A big bat , flapping slower, less calls emitted.
Stills from some video captured in Hants using a thermal camera.
They show things we;'ve not seen before. The bright blob is the
open mouth of a bat, so its calling at that time. With stop-frame
we can do some measurements to establish the bats speed.
Each species of bat emits a different sound as heard in a
bat detector. Recent software has been developed for the analysis
software , where it can make a good stab at determining what species of
bat in the sample. For a single bat flying on its own , it tends to be right
more than wrong at this. But to be sure you have to analyse the
waveforms yourself comparing to specifications.
My recording system has a lanyard attached to my clothing as a previous bit of kit decided to
separate itself while walking thru a marsh and i lost it.
A considerable amount of ultrasound comes from just moving a bunch
of keys , its also picking up my voice . The audio spectrum analyser goes
from 10 to 120KHz on this one. There isalso an oscillogram trace of the
sounds . Also a sonogram representing the pressure and duration and frequency of the
sound. Yoyu can tune it as its a heterodyne receiver , for the best human sound
for which ever animal you are looking for. For a soprano pipestrelle you
would put it at 56KHz for the best representation of what we consider to be
that bat noise. Beause what we here is the bat call beating against a frequency
i nthe kit and depending on how the kit is tuned you can change the character of
the sound we hear, bu tthe sonogram will remain the same.
Records into the iPad or you can have an Android version of it.
You can transfer the files to a pc and run the scientific analysis
software , to establish exactly what you have. All relatively
affordable. A screen-scrape form my ipad , its set to 59.9KHz
as its soprano pipastrelles i get in my garden. Its set to
heterodyne but it could be set to yime-expansion . It can record the
GPS location , you can add notations in the field if you wish.
With its stab at identifying , the code for identifying a soprano.
Talking through the sound-file. They tend to start at high f
and drop in f , then a more sustained burst and we are starting to
understand the significance of all that. Their environment is trying to
navigate thru space while flying , building a sound picture
of what is around them. They do this every time they flap
their wings, a shout and hear a returning echo.
We believe they can discern the distance and identify prey species
very exactly, otherwise they could not capture and eat them.
Al lthis from the characteristics in the call and echo. The calls get
stronger or weeker , asit flies along it moves its head side to
side getting direction info. If you receive a strong signao, thr
bat is probably pointing its head directly to the mic. A wekaer
signal could be turned away or gone behind a tree. As it closes
in on its prey you get a feeding buzz , about every 70mS
there is a pulse coming thru. When it detets a prey it changes its
call , closer spacing of pulses and the f starts to drop. We believe this
is because as it nears an item it needs more data as to where tat prey
item is , to establish the best picture.
There are data loggers you can strap to a tree and leave for a couple of
weeks. Gaininginfo on all that passes by, thousands of files.
Thrn you need pro software to plug into and do the analysis
for you. A curious thing to emerge for one of our researchers , when this is done early summer ,
get regular call patterns that sounded very much like a bat and the software
had a stab at identifying an obscure bat that we don't get in the UK.
Returning to the original site it was established that it was a VW Polo
reversing into someon's driveway and it was the signature of their parking
sensors. The earlier parking-assist electronics was a simple blast of ultrasound and
then listen for the return, now realise they can get more
accuracy , by dropping the f after first perceiving an object.
But the bats got there 50 or 100 million years ago.
The final part of the feeding buzz is well below the normal f.
The bright colours in this display are the highest intensity when the
bat is facing the mic. The final buzz is very rapid pulses but dropping to 30KHz at the
very end. So a lot is going on. Since we've had this kit , bats that look
very similar or identical in the hand, we've discovered are separate species.
The common pipastrelle is 43KHz and the soprano pip are 54KHz and there is
another pip , with slightly different colouration is 38 KHz, bu tonl;y easily
discernable by their call.
It is loud, just as well we cant hear ultrasound , as its over 100dB
when they call. So if they make that amount of noise and they depend on
hearing the return echo from something as small as a midge
, why don't they deafen themselves making the first noise and retain the
ability to hear a feint echo. Their ears are different to ours , the middle ear
muscle contracts and effectively dislocates the bones that connect thru
to the ear-drum. So they cant hear their own voice when they make the
initial noise. It all gets reconnected within 6 mS , to hear a moththat is
1m in front of them.
Using a thermal imaging camera we can see what is going on. An aside about a
snail expert who published a paper on snails in 1962 , describing a new snail he'd
found in a bat cave. Of these 2 snails one had a clockwise and the
other anti-clockwise bias, very unusual in snails so worthy of a paper.
Unfortunately what he'd found were cohlea of the great horseshoe bat,
that had fallen out of the skull because tissue had rotted away
and nothing left of connective tissue. He later wrote a retraction, hey-ho, thats science.
The next endeavour of bat research in Hampshire is the Merlin thermal camera.
The same camera system as used on likes of BBC SpringWatch and AutumnWatch.
Ian Watson uses one in our research , he works for the company that
makes them. The object lens is a large single crystal of Germanium
, as of the early transistor construction. It is a semi-conductor material
but also anothe rproperty that it won't transmit visible light , only
thermal infra-red. Its a zoom lens , its sensor requires a way round the
noise generated by itself for feint signals, signal to noise ratio.
One of the few ways around this is to cool things down , in there cooled
with liquid nitrogen and a Stirling compressor to keep the nitrogen
as liquid. Works extremely well and does not bother the bats .
When you point it at nightjars in the New Forest , they think
its a moth and come over and try and eat the camera.
The also adapted it with a touch screen on the back so it can
be operated at the camera. Its nit using the area of IR used by
security cameras , wher eyou see a dull red glow associated
with them as the illuminator. This isa giveaway to creatures. There is a 960nm
version, that makes them invisible but more expensive and not as sensitive.
The Merlin uses long wave IR and because of the whizzy electronics it
needs no external light, so completely passive. Most nocturnal
animals will see a "dark light" illuminator , but this is
totally invisible to creatures.
Video sequences.
One pixel is one midge , the fall guy in this video. The bat enters
fixes an echo on the midge , mouth open , echo locating towards it.
It catches it in its calthar tail appendage, and bearing in mind that it
stays in the sky by calling, it does this within a wing beat.
All very quick.
Q: Do they always use their tail rather than mouth to catch?
I would not like tosay always, some are caught in the mouth.
Its been recently discovered and confirmed in N Hants that Nateras bats
are grazing on terrestrial bugs. Either landing on a tree before dropping to
the ground and catching by mouth as use of tail on the ground is not practical.
Eating things like woodlice, spiders. DNA analysis has shown they are eating
lepidoptera so moths and butterflies but remains of food in droppings contained the mandibles
of caterpillars and front claws of caterpillars. A lot is being discovered
at a fast rate at the moment.
Another video, making a slight error in tracking and doing a sort
of Fozby-flop before catching it.
Q: Is it detecting an object or the vibrating wings of a prey, I was wondering what their
resolution is?
I'd imagine its detecting an object.
Pipastrelles are detecting by echo-location. Horse-shoe bats hang up
and listen for the rustle of wing scales of moths and home in on that. So they have a softer
call, much higher f, quite characteristic.
So a spectrogram of a chase and a capture , the arrow will run along the
calls , between wing beats along with the video of the bat and midge.
The echolocation character changes very rapidly on the homing in
section. The 60KHz drops to 40KHz and the period drops from 30mS to
7mS and then down to 5. So that is the tecnique required to precisely home in
on that prey item and capture within the capture area of its body.
They obviously are successful at this operation as so many bats are around.
Socialising and catching prey at night, they largely avoud predation themselves .
There tends to be ambush predators of bats . Cats can hear up to 60KHz so if they
get access onto a roof say , where there is a bat roost, they will sit
outside and grab them on emerging from the roof. A lot of bats appear
at bat hospitals , with torn wings from cats. Amazingly if looked after and not
too injured, they will heal up and fly again. In the wild they become prey items
themselves on the ground.
Te hobby bird is a notable bat catching bird, going for bats at sunset.
Bats don't have protection then , because the hobby will come at them from
behind as the bat is looking forwards. I saw such an encounter at
Swanwick lakes earlier this year. The hobby was coming after a
bat , took a swipe at it, the bat dropped like a stone, presumably torn wing
and fell in the lake so sad for the bat and the hobby as neither was successful.
We've not had the disease that is devastating the USA bat population.
Q: Is it true that insects have anti-ultrasonic techniques?
They do indeed. I attempted to video long-eared bats using one
of those IR security cameras. I got a large LED illuminator lantern
and shone into the distance, all I got was a nice
pattrrn of red dots on the distant wall. So in Poundland I got a book
magnifier fresnel lens and cutting it down and placing over the
lantern and tuning the separation I got a nice colimated beam
of IR coming out. Pointing this at a roost we could see the long-eared
bats doing their thing, better than we had before. Nowhere near as good as
the Merlin camera . Part of that sequence is moths just dropping out of the
sky yellow underwings? the principal prey of brown long-ear bats.
They had developed the ability of hearingthe bats coming after them .
The long-ears have quite a quiet call and its remarkable that moths could
hear this. Perhaps not too well as the yellow underwings are still the principal
prey of brown long-ear bats. Thats the only one I'm aware of but there could well
be others. With moths and horse-shoe bats, if they stay perfectly still then
those bats will not find them , but not future in being innaminate.
What is the lifespan of bats?
All being well quite a long time, compared to terrestrial shrews and mice measured in months
to a year or two, bats can go for a few years. I believe there is
evidence of 10 to 15 year lifespan. What they're doing is ringing bats, giving the
data to establish that. But you have to capture such ringed bats twice to get that data.
Bats being such small animals there is limitations to what weight you can
hang on them both legally and physically without disturbing them
too much. I have been involved with radio-tracking and the guideline for that
is, a weight limit not exceeding 10% of the weight of the animal.
So for an animal only weighing 5gm, believe it or not half-gram
radios do exist. Then the next difficulty is tracking
long eared bats doing their thing. You have a large UHF Yaggi TV type aerial
with many elements, that you are trying to keep up with them. It is just possible to use them but
difficult to get the data returned. Some other data from a tunnel
on the Basingstoke canal where they've used long-life thermal sensors on the
bats for during hibernation, they have a small aerial that sticks out.
When a bat gets between bricks , the hair-like bit of wire sticking out is
all you can see of them.
Q: What are their temperature in the roost, you say the tunnel background is 10 deg C?
It is written up, Paul Hope has written 3 papers on the Greywell Tunnel monitoring,
the temp does drop quite low and fitter bats with a higher body mass are better
able to survive longer and ventured deeper into the tunnel. Weaker ones roosted
nearer the tunnel mouth , exposing themselves perhaps to more predation
by things coming into the tunnel but this does give them an outside awareness.
Near the mouth there is temp fluctuation dependendent on what was
happening outside . This is where combined with their body-clocks, those
bats woke up at sunset all thru uthe winter, despite that time each day changing
over the winter. So something tells them the optimal time to go
out to avoid predation and also that their food source will
be on the wing then.
Q: We've used Pulsar heatscopes, are you aware of those, they're mot FLIR cameras,
you can see large animals 2 or 300 metres away. You can see bats in caves and
forests.
No personal knowledge, Do they give a true representative image .
Q: They require a setting for differential heat , so no use if the bat was the
same temp as the rock.
When Ian uses the Merlin he sets it so you get a monochrome display .
It is otherwise possible to infer other data by using a colour option , not
true colour , a false colour image.
Q: If you bring up your pic of a bat again , as I've not seen these sort of images before.
If you home in on a view where it shows the junction at a wing, thats a hotspot
is it not?
Thats where the muscle is concentrated, energy is escaping thru the fur.
They are on you-tube , put in brown long-eared as a keyword. He's done
good stuff on owls and how they present themselves. They're hotspots on the
wings and legs and when an owl lands it thermally hides all that so
the only emerging hotspots are its eyes. And when it sees something it tends to close them
down as well.
Some other research I'm aware of involves the sense-hairs on small
mammals. Shrews, mice , rabbits they allhave a feature in their
fur of a long hair sticking out. Bats don't have that, moles neither.
Al terrestrial mammals that are above ground that are often nocturnal or
diurnal , have this . Ian with some other people have looked at this
piece of fur and its the correct shape and correct cellular structure , tuned
to the f of energy coming from an owl's eyes. The eyes are seeing photons from
its surroundings but also radiating heat from its skull via its retina.
So these animals seem to have developed a 360 degree sensor for this
energy. So triggering a response in the intended prey anomal.
So owls tend to mask their heat sources immediatels on landing.
When homing in on mouse an owl restricts its eyes to minimise this
outgoing effect.
Q: Some species of viper can detect that on a mouse.
Its interesting how these effects come about.
With that video there is a particular make of trail cam that is using
nearIR but its also emitting energy from the thermal part of the
spectrum . Not part of its design but its doing it. Point one of these at a
bird feeder , that thermal energy can be masked by placing a piece
of glass over it. Do that and the mice feed happily but take the glass away
, the mice will come in but only as far as sensing that energy.
They freeze and then disappear, having sensed a threat. Maybe the
same with other makes, I've not so tested. Its a fascinating area.
When I frst met Ian at Swanwick Lake, I was late
so he'd set up the kit anyway without knowing where to point.
He found a wood pigeon in a tree , but also a bees nest and they
were still active at night, coming in and out of the entrance but at night.
I'm not sure whether people are aware of that insect activity.
The most common bats at that time and place were Daubenton bats
, taking insect prey near or landing on the water.
So I could see the quartering of the bats hunting , far better than using a
torch .
Q: I assume the military take an interest in this?
Yes they paid for the developement. Its how we get this whizzy stuff.
A phrnominal amount of money developing that camera. Its not too
difficult to imagine what the military use them for.
Q: With defense industries in mind. The sound produced by bats is it a
chirp , the rising cadence of frequency in a burst, ie not a constant f.?
Apparently a chirp spectrum structuere is the easiest form of
noise to distinguish from other noises around so used in defense industry applications
but used by bats for the same reason perhaps.?
It depends on the bat but it is a chirp, different f and different amplitude
properties so combined AM and FM. One bugbear of using acoustic
bat detectors is the amount of ultrasonic background noise from crickets and
grasshoppers.
Q: They generate the noise by rubbing their legs or kness together but is the generator
for bats the same as humans , but scaled down, so vocal chord?
I'm not sure about bats but birds have 2 voice boxes , which allows them
to produce the range of melodious songs, maybe bats are similar.
I've tried to find the details of the innards of a bats ear but no success so
far.
Q: You say they have good eyesight so are they disturbed by
flashes of light people doing bat counts say?
It would appear not. The theory is all creatures are accustomed to
seeing lightning flashes in their day to day existance. This was one
of the tenets of bird photography in the early days. I visited someone
who'd moved out of London to a small chicken and egg farm in Devon in the 70s.
All those chickens in rearing houses , so I thought I'd tsake a pic of this .
As a book on bird photography of the time by Eric Hoskins,
that flash light does not bother birds. I took my flash picture and
all hell let loose , dust and feathers everywhere.
Q: What else do they eat other than midges?
Depends on their size. The tiny pipastrelle ones , they hoover up
midges. If you're at a river bank and some are circling you , then
you've attracted a cloud of midges that the bats then hoover up.
The next size up, brown long-ears like moths , the yellow underwings .
The big ones Serotines will take the larger beetles, chafers and
stag-beetles. Whatever fits their niche. Daubentons batrs they
are around water so taking may-flies . Nataras bats which aren't very big
take caterpillars, spiders , wood-luice and moths. And take a lot of them,
so economic and ecological value is quite signoficant. Away from the UK,
we would not have any figs as those trees are all pollinated by bats.
I think coffee is also polinated by bats, so no coffee if not for bats.
All our bats are insectovours.
Supplemental videos
A news item from a few years ago. A bat that was ringed in the UK was found dead
at a farm in Holland. May have died of old age or from having a fruit cage
fall on it. THe first evidence of bat migration from or to these
shores. Nathusias bats , with strong research on them in Hants and Dorset
slightly darker pipastrelle , except for its dentine and sexual organs
you could not distinguish. Its been known for a long time that they
migrated over the European landmass , from Baltic states thru Poland, Germany and Belgium
and some winter in Spain, then go back again.
In th e UK they have been breeding and have been trying to establish the
migration thru the UK on a yearly basis . So from Latvia and Lithuania
to us. They've been picked up on gas platforms in the North Sea. The Natioanal
Trust in Norfolk they've erected impressive aerial arrays to pick up
signals from radio transmitters fitted in Latvia, so serious work.
More locally , Dorset , a guy who has found Nathusias
at a lake near Bournemouth . They follow coastlines , navigating between the
sea-shore and the first obstruction . So if a beach with cliffs they will be on
the beach which is not where bat enthusiasts spend their time. He
found a pinch point, a beach that was privately owned. He set up some bat
monitoring kit there as he was keen to establish they were travelling all
in one direction. Normally bats fly all over the place.
They were all coming from the east , one direction. Pretty
strong evidence of a movement probably migrational, of bats spending the
summer in the Baltic states.
A distribution map produced by European researchers, we were not in
the loop at that time as no UK evidence then. We in Hants are more
onto this possibility and with improved kit available, for identifying
Nathusias bats say. A recent plot of where Nathusias have been
found in the UK, the larger numbers going along the coast may
be migratory ones. So coming to us in Hampshire, where from is unknown as yet.
Hilsea Lines north Portsmouth is quite wooded and they've put up
bat boxes that are quite small but they can get 50 bats in one of them?
Yes often the case. The guy who was doing that at Hilsea was
recording at Privett Tunnel. He's the ranger there and he manages all
those boxes. Noctule bats are like the Stukers of bats, fly very high
,sense a moth and drop down on it. Too high to see them but you can pick them up
because their call is so loud.
Q:Can you see the heat signature of a hole before the bats emerge?
I'm aware of where a nightjar flew off there was a warm patch
on the ground afterward. I'm not sure its true for bats as well.
Q: Heat coming out of the hole as distinct from directly off bats?
I don't think thats been observed. They are well insulated though.
You can initially see via Ian's video warm arms and legs and torso from where they've
been in the roost. But on return the body would still be warm but not arms or legs.
A video I took with my IR setup and IR illuminator of
someone's roof and brown lon-eared. There is a tumble drier effect. I was worried my light
was causing them to be nervous on emerging. But not so, they do a circling
within the roost before emerging, to warm up their wings. Using the
professional passive IR camera , the same behaviour is observed.
Prior to this recording we were trying to visually do a count , but by 10
o'clock no one could see them directly but still activity shown
on my laptop display of the IR camera. They come out slowly in
ones and twos to forage, but as soon as a drop of rain they all
bundle bag in. In Ian's video you can see the roost is quite warm ,
whether that is relating to thermal insulation of the house , but I
doubt its from the bats. A lot of heat from their faces and ears.
The tregus , brown long-ears have , like a larger ear, presumably allows them
to gather more sound, going with their requirement of sending out less call
than pipastrelles. A similar feature to what owls have. When they roost
, the ears fold down and its only the treguses sticking up.
The arms right out to the wrist are quite warm as is the body and legs.
The camerawith 2 people at it, about 30m from the roof aperture and the bats were
well used to the house owners being around.
Has he comparable pictures of greater and lesser horse-shoe?
Yes, for greater and a maternity roost with pups emerging
after the females. Its not publically available yet as it
was filmed for an upcoming ch5 program , though I have seen it.
He has serotine and noctule roosts , pipastrelles as well.
He's done so well to get such detail with animals that are so small
and so quick.
Ian Baker? videos on the internet , search for "brown long-ear" , he has about 11
such videos so far
W153
Tuesday 17 Dec 2019, Dr Andrew Yool, NOC, Southampton- Turning
plankton into numbers: How life in the ocean becomes part of our
climate models (rescheduled from October).
I work at the NOC in a group called marine systems modelling.
Modelling living systems in the ocean and how that becomes part of climate
models. The NOC was built to house part of the university and a government
lab that was i believe at Wormley sussex. About 190 staff and also students, covering
biology , physics, large geology group , technology and modelling that I'm
part of. We have a sister institute in Liverpool , in Soton we focus on
the deep oceans away from the shelves, greater depth than 200m.
We build models of the ocean ot understand how the ocean
works and how it interacts with the climate. We add living systems to
these more physics models. Some of our model outputs are used to
drive socio-economic stuff. People interested i nfisheries for instance
take stuff from our models. Although I work in a mathematical
modelling department I'm originally a biologist. I'm not so
interested in parts of the ocean, only interested in the whole.
Marine biogeochemistry. How life runs and is run on the ocean
chemistry. Biology is an important part of that. Then I will speak
a bit about ecological modelling. Finally the bigger picture, how our
work fits into global climate research. So biogeochemistry is a
portmanteaux of biology , geology and chemistry. We take input from
all 3 disciplines , embedded in the physics of the ocean.
Despite what we think of marine biology consisting of animals and plants of
the sea, sharks and shellfish etc is just a small part of the
living systems in the ocean. 3 main living groups on the
Earth, the eukaroytes
like us , typically large multi-cellular animals plants and fungi,
bacteria and a type of bacteria more related to us than
the other bacteria called the archaea. We tend to think of the
large animals as creatures of the ocean , but there are fungi
in the ocean, algae, protozoa that are small single cell animals,
archaea bacteria, cyanobacteria (that closes the lake on Southampton
Common sometimes and its poisonous).
Size is significant to life in the ocean compared toon land. On land the
most dominant animals are large, trees, flowers, grass or us.
In the ocean you do get large animals like whales but the majority is
much smaller , typically microscpic. So why so much small stuff in the
ocean. The equivalent of plants in the ocean phytoplankton , need light
to grow and light is only in the upper layer of the ocean. Light is attenuated
down th ewater column very quickly. Only light is above 100 or 200 m
of depth. So one problem is to maintain your bouyancy so you
don;t sink to the depths. Larger things will soon sink and remove themselves
. For those living on land , in air, you have a small boundary layer
around you. As you move thru the air , the speed of the air drops
to zero on your skin surface. In water, with its viscosity , the boundary
layer is more important. If you try to suck nutrient out of the water
, the boundary layetr effectively blocks htat. The bigger you are , the
bigger the boundary layer again favours you being small.
In the ocean and being big, the mechanical stresses of being
stretched and strained by ocean currents being mor eviscous ,
it is harder to be big without being damaged by those strains.
If you're small you just get swept along by the current.
Things at the bottom of the food-web , the majority are small ,
thetr iss still a lot of diversity. There ar eloads of free-living single cells
throughout their life cycle, they divide and the daughter cells go
off. Sometimes asexual and just keep dividing and sometimes
buddying up with something else and have normal sex.
Sometimes they exist in colony forms , sometimes as small
chains . A consequence of that is, make yourself a bit bigger , that makes it a
bit harder for things to eat you, as they wont fit in the mouth.
One reason to be in chains or spheres.
Sometimes they live in association with other organisms , like corals.
They take phytoplankton from the water , and basically enslaving it
inside themselves to make food for them. There are also organisms that
may look like plants or may look like animals but do a bit of both
and pick and choose what they do, dependent on the circumstances.
Cyanobacteria are common in tropical regions . An important group
is the diatoms , they're eukaroytes like us . They build their walls
from silicon , its an ingredient of toothpaste . A particular role in the
ocean flowerings of early spring. The Cochlophores? , as in hte
White cliffs of Dover, which build their cell walls from
calcium carbonate. When these bloom they make the water quite
milky and you can easily see from space or even from ground level
in the water. Dinoflagellates ,eukaryotes, make their walls
in a different way, either plants or animals , changing their
eating habits on change of conditions. Everything rests on
phytoplankton at the bottom of the food chain.
The next level up, as animals , Krill dominant in the Southern
Ocean around Atartica. Cophopods , crustaceans like krill but
much less familiar , no bigger forms of them that we might see
in a seafood dish. These are particularly important in hte North
Atlantic. The pterapod related to molluscs and snails ,
a swimming pterrapod with wings, consuming plankton.
Foreneferon? single-cell surrounded usually by long
spines , this one eating the remains of a cophopod.
Similarly a radiolarian? bit like diatoms ,also uses silicaon,
eats phyyoplankton (pp)usually. All these are impoortant in the
ocean but you will probsbly be unfamiliar with them.
zooplankton at the top of the food-chain and phytoplanktom
at tjhe bottom. We want to know what is driving this chain
of consumption. What is controlling the growth of pp.
You have to have pp at the bottom , and they work in a similar way
as plants on land. Their requirements ar elight, nutrients
and CO2. So a lot of light at the surface , below 100m
running out of light. Nutrients are the likes of nitrates,
phosphates, silicates . Simple chemicals but to build them up needs energy
to make more complicated compounds like proteins. Any organic
material will be built from these basic nutrients.
They occur in particular vertical apportionment of the ocean.
Light is high at the top, nutrients generally high at the bottom.
Mixing is important in the ocean . At the surface the mixing is from
turbulant mixing with the atmosphere, momentum transfer between
ocean and atmosphere , into turbulent kinetic energy. That tends to
mix the nutrients from deeper in the water column up to the surface.
You then get high light and high nutrients in the same place.
For an individual pp being mixed, the lenght of the water column,
half the time its dark and half the time is light, not very good
growing conditions. The precise amount of mixing is important,
so say the wind drops , like when the weather improves from winter into
spring , then summer, the pp is trapped at the surface with nutrient and light, you
get the blooms. pp blooms occur in most parts of the ocean
around springtime locally. pp bloom later translates into zooplankton (zp)
bloom. Notthe same in all oceans, the tropical ocean is very good light
all year round , heated strongly , so a layer of hot water
over cold water , which is difficult to mix. there the nutrients get stuck in the
deep ocean and nothing happening across the surface of the tropical ocean.
The range of mixig is important, we don't have an analogue for that on land.
The variation of light in the ocean varies because of the sun inclination
to the Earth , varying seasonally.
Concentration of nutrients vary a lot across the oceans. Nitrate is pivotal
in the ocean , for makling proteins. A sytong geographic pattern, the high latitudes
N and S is high , low latitudes with a few exceptions is low. So this controls the
productivity in the ocean. The background around which the light requirement
operates. It means that large areas of the oceans ar eeffectively
deserts. No matter how much light they get, ther eis no nutrient ,
so no growth. The exceptions in the tropics is where there is upwelling
regions, come from the deep, brough to the surface by
ocean currents. As oceanogrphers we tend to think of the tropics
as deserts. Almost equivalent to deserts on land , like deserts on land are missing
water, deserts in the oceans are missing nutrients.
Q: Where does all the nitrates come from in the southerns Ocean?
There is the thermohaline circulation , an overturning of
the ocean . Water moves from the surface t the deep ocean , driven
by a number of things but principally by ocean density , so by salinity
and temp of the water. Differences in density in different parts of the world .
So north Atlantic is cold and it can be very salty as well, water coming up the
Gulf Stream evaporates , increasing the salt concentration . So th very high N
Atlantic has water that is cold and salty, so more dense and subducts
into the ocean . This process can take hundreds and even thousands of years
i nthe South Pacific.
In othe rparts of the ocean there is the reverse and water comes up cold
, so any area of upwelling particularly in the Pacific you tend to have cold water.
That can contrast strongly to the climate adjascent to that. You can have the warmest
climate on land but just next door , can have very cold up-welled water.
Upwelling brings nutrients to the surface, which then fuels pp
at the surface. Nothing lasts for ever, the nutrients run out, they die
and the reverese process then happens, sinking back into the
deep, the biological pump. Mixing also plays a role here as well .
Not all nutrients important in the ocean, originate in the ocean.
Map of dust deporition around the world. Dust is picked up from
dry arid regions of the Earth , carried in the air and gets
deposited on both land and sea. In the ocean its role is in
transfering iron to the ocean. So a lot in the N Atlantic
from the Sahara. Also around the deserts off Australia and off
S America.
Again relating to why nitrates are so high in the southern ocean.
Antartica is the driest continent on Earth , no dust as its covered in ice.
You can move continuously in the water around Antartica , in a circle
without bumping into land. The predominant air currents there
are also around the Earth as well. Air currents carry dust don't reach
the southern ocean , so no iron depositing out. Without iron , the other
nutrients aren't consumed and tend to build up.
This story is a bit more complicated , but the general gist.
There is an idea that one of the things that drive ice-age cycles in the Earth climate,
is the availablity of iron from Antartica. Iron is considered a trigger , hence why
some people think a solution ot the climate crisis is to drop iron in the oceans.
I won't go into that.
Life in the ocean is driven by micro-organisms, the pp is the primary
provider in oceans like trees are on land. Lots of different types
and lifestyles of pp and the larger grazers. They can be eaten individually
or the gaping jaws of larger animals. Productivity is driven
by where there is high liight and high nutrients and the abundance of both
is driven by physical processes. Can be local scale of wind causing mor e
mixing or the large thermo-haline circulation . Deposition of dust is on
enormous scales. Some nutrients reach ocean surface from below, some from
above, also from rivers and from within ceans by hydrothermal vents.
For pp some can synthesise nitrate from nitrogen from the air that gets
into the ocean. But those types requores othe rthings to make their life
easier.
Ecosystem modelling.
We collect facts about different bits of the world, observations, measurements,
experiments, to build an understanding og what is going on.
Modelling is stitching all that together into a fabric of how we think
its working. Typically we use maths, but also sometimes a conceptual
model of how it works. We write down equations. Sometimes these can
be solved by pen and paper, if small enough model and few equations.
Yhe real worlsd is complex and so our models we build
and very quickly the miodel becomes harder to solve by hand.
So we give a compute rthe equations and get it to solve it. It is
expensive to carry out experimnts in the real world . So in the
prototyping of cars aerodynamics its easier to model i na computer than build variants of
model cars and test in a wind tunnel. Some experiments you dont
want to do, like flooding of people or nuclear weapons testing.
Using computers to determine forces, or quantities of materials and what happens
to it. Some things are impossible to do, a hurricane in a lab is impossible.
So we would have to confine ourself to observations only and not understand it fully
or try it in a computer simulation. Closest to the talk here is trying to model
climate change and to look into the future. As no time machines to peak into
the future, computers are the next best, to understand what could happen.
So for ecosystem modelling what constituents of the world are the
most important actors, doing the most work, the most abundant.
The most important are at the bottom of the food-chain ,pp and zp.
What controls them and what makes their life easier, why do they
grow in some places and not in others, due to light and nutrients.
Long before computer modelling, people had studied these systems
and knew they were important. We tsake the actors, the controlling factors,
stitch together to form multiple equations. The multiple equations I use ,
barely discernable on one page. The bottom concerns nutrients, nitrates,
ammonia and iron, silicon , carbon. Differnt types of pp much simplified
to diatoms and everything else. THere is always a point in modelling where you
have to say the world is too complicated , lets just make an assumption.
Thenthe zp and in this model we say there is small zp and big zp
and that controls the nature of the food-web. Small diatoms are eaten by
small zp and also eaten by large zp bu tlarge zp will eat other animals
as well. Everything must become dead material , and via bacterial
action that becomes nutrients. The food-web. No fish involved in this
, although important to us humans, in the ocean they are relatively
unimportant. As far as pp are concerned they may as well not be there,
being such a small role there. Each box in the model has a function in
life and each has its own equation, involving a series of terms each of which
describes some aspect of their life. Light and nutrient has a very simple function
as light goes u[p the growth rate of pp goes up as well. There is saturation
so above a certain point they don't grow faster. Same is true for
additional nutrient, it saturates, comes to a point
where it cannot be used. These equations are based on lab experiments.
Taking samples of water from the sea and vary the light and
nutrients. Sometimes from more theoretical things . The bottom of the food-chain
is relatively somple because pp is interested in little other than
light and nutrient. But go up the food-chain , they start getting interested in
othe rthings and relationships get more complicated and more sketchy.
Physics is important to things on land bat in the ocean its absolutely
critical. For modelling pp and the wider ocean its critical
we do a good job with the physics. For the ocean the key actors
ar etemp and salinity. We know how those are affected by the likes of solar
heating, evaporation , rainfall, winds and what the atmosphere is doing.
Just as we simplify the life of the ocean down ot a few boxes,
something similar is done with ocean physics. Its much simpler in a
way , the equations describing how water behaves, how it warms up
with applied heat, how salinity changes with fresh water supply.
These things are better understood . As a result physical models are
usually more accurate than the biological models.
To model the whole oceans we chop the world int small boxes.
Each box is a little world, they're each connected to each other.
They're affected by the likes of ocean currents and ocean mixing.
We simplify the processes going on. Each box can be tens or
100s of km in size, then inside that, everything is the same.
So a rather crude representation of the world. For every box we
calculate how much heat is being appliued, how much
fresh water applied, how much evaporation, density
changes and how that affects ocean circulation.
The boxes speak to each other , move forward in time
and repeat the whole process again. Doing this we end up
simulation how the ocean works.
A video example of the model we use. It starts from rest and we say
go. Fast and slow moving currents develop and you start to
see familiar features like the Gulf Stream , Equatorial upwelling,
I mentioned earlier. The pirushiboo? up the side of
Japan and analogue of the gulfstram but in the Pacific.
Wriggly features and lots of small-scale stuff. Patches appear
and disappear , which is weather systems passing over the surface.
In some parts o fthe ocean it gets very complicated, sometimes rings form .
This video is a complete fiction , nothing is real, its just a representation
of what the real oceans are doing. We compare how our models
perform against observations from reality. We can then make our models
better and ascertain how good our models are.
Pointing out the Antartic circumpolar current, the one place in the
world where water can rotate without touching land. All the other
oceans are bounded east and west by land masses.
The clock shows it starting 1978 up to close to the present day.
We tell the model what the surface conditions were like in say
1980 , where the rainfal was, the solar heating in all the different
parts of the world. This video just shows the ocean surface.
Underneath all the way down to the sea floor , the model is also processing.
A thing you can use the model for , as with ships we've only sampled
tiny parts of the oceans, we can retrospectively look at what
was happening in some part of the ocean , say 3000m down without
actually going there. As long as we can trust our model from
agreement elsewhere to reality . This is one of our best models,
to 1/12 degree resolution so 7-8km for eah box. We don't always
use that resolution like 20km. 20km model gives most of the
same features. But boxes of 100km can be used but not
as good a job. Unfortunately the 100km type models are the ones
used for climate change forecasting.
Us simulating the seasonal growth of pp and you start to see opposite
patterns developing in the north and south. We're telling the model how
much light and nutrient there is and they grow, are eaten or die,
the full cycle. Chlorophyl a pigment in plants , here in pp can be
seen from space. So we can compare our models to what we see
from space and can decide if we're doing a good job or not.
If not , we change our models and try again.
Its all very well having a big grab-bag of facts , but we need to
distill those facts down to a coherent story , using models to do that.
Our understanding is never complete, always approxiamation,
always wrong. A movie like that is not something you can
do on the back of a fag pack.
If they do a good job of representqation then you try and use them
to try and understand things you cannot observe, or difficult to observe
or at scales that are difficult to observe. A ship can only explore one
tiny point but at larger scales we might understand processes that
are important, that go on at those scales. Or we can simulate things we cannot
go to , like the future.
So how do we use our models in a time-machine function. One word is carbon.
CO2 in the air affects the radiative properties of the ocean. The C in the
Earth systems. Although we focus on CO2 in the atmospher , as that is
where it affects our climate, only a small amount of C is in the atm,
less than 2% is there. A bit more on land , in trees and soil but by far
the greatest in the active part of the Earth
is in the ocean (not including the Earth interior
as it does not interact on a timescale relevant to us).
How the C gets there is very important.
About half of the C going into the atm is still staying in the atm .
About 1/4 is going into the ocean and being stored there. So its slowing
down climate change, absorbing into the ocean the CO2 that would
otherwise be in the atm and warming the climate even more.
The ocean is 70% of the Earth surface and if it was not there we'd have noticed
climate change a long time ago. In models , if you remove the
ocean , cthat change occurs very quickly. We are lucky to have this
storing in the ocean . 2 main mechanisms. The solubility pump ,
the solubility of CO2 in water . As in fizzy drinks, you can have too
much CO2 in fizzy drink and it bubbles out. So a way of moving CO2 around, its
absorbed into cold water and when the water is warmed , it outgases.
Its tied in to the thermo-saline circulation and creates a physical
pump in the ocean . The majority of C in the ocean is driven
by thios pump. Nutrients don't travel in the ocean ,when things die ,
they sink and take C with them, the biological pump. Biological
activity at the surface, die and sink . The sunk C eventually
becomes disolved C in the ocean , the same way as with
nutrients, it can return to the ocean surface by current circuklation.
Increase the rate of CO2 input to the atm requires the rate of
take-up in the ocean to increase. The biological pump is not
bothered by CO2. CO2 is abundant in the ocean, having mor eof it,
makes no difference. If the strength of the biological pump
changes , if it weakens, that will transfer more of life's C
into the ocean interior . From our pp studies in how it responds
to CC , we expect the biological pump to weaken, primarily becaus ethe
upwelling of nutriients will decline. What w eexpect to happen as the
oceans warm , they warm from the top . This makes the surface more
stratified , the surface ocean communicates less with the deep
ocean. The return of nutrients from the deep to the surface is
weakened. Then the ingassing and outgassing of CO2 by yhr
biological pump will weaken. CO2 will tend to stay
in the atmosphere more and so enhanced climate change.
So although the biological pump is not the main driver for CO2 into
the oceaan, it can still be imprtant, in the future.
The concentration gradient between ocean and land is important.
Wehave to put our undertanding of the ocean into a wider context.
Over the last 30 years there's been a movement towards making our
models have all aspects of the Earth in them.
As time has passed we've added more and more complexity to
initially just the atmosphere. The ocean was one of the first to be added as
they realised that to model the atm , you need to understand the ocean,
as its a great reservoir of heat. Then you have to add sea-ice and before long
you are ading evedrything. Current Earth models include atm, ocean, land
, ice and the living systems. Living systems are important because of its
connection to the C cycle. As they are so complex you find Earth-system
models are made up of bits of models, studied by people who stdy the atm ,
people who study the oceans, they work separately and bring their models
together. The one I work on now is a new one called UKES1, Uk Earth System 1,
ther eis land physics, land geochemistry like the ocean geochem
but different components as trees and animals giving a different setting.
We also have a model called Triffid that is competition
between trees. On the ocean side of the model there is Medusa,
I showed video of earlier. Dealing with the biochemistry of the nutrients , pp
and zp. Iys coupled to a physical model called Nemo and also an
ice model in there for the high latitudes.
For the atm you have to consider chemistry , how different chemicals
are transported through the atm. Aerosols are important, role of clouds .
C is behind all these things, how C flows between these ? is very important.
Some work I've been doing, intohow we think the biological pump
will work in the future. A pattern of low C being put down into the
ocean , the deserts of the ocean and high elsewhere. When the oceans
stratify, the biological pump weakens more and more, driven
by the stratification. Running from the year 2000 to 2100
under a range of different scenarios. Going from a benign scenario
up to a business as usual scenario, showing the strongest efffects.
The policy behind the work on these models.
For the UN IPCC established more than 30 years ago , to
assess climate research . Every couple of years they gather, read thru
their research and try to produce a report on it. There is one due in 2021
being finalised at the moment. The results of some of these models wil
be used in the report to understand what sort of climate we could
have under these different scenarios. The scenarios are performed by
a completely separate organistion called SEAMIP ? its like the Olympic
Games but for system models. They provide a forum whereby we can
compare different models, 20 to 30 different ones. They're difficult to
buil d and to run , to maintain and operate. Most coutries have
perhaps one or two , so relatively few around the world. Because there is
a lot of uncertainty in the models, as a get around, is to use a number of
models and try them out. Making different assumptions, evaluating the results you
get. Having different models doing their differnet thing , with the same shared
assumptions . SEAMIP forces everyone to compete in the same event,
the event being things like 4x CO2 and see what happens. This gives us the
range of model behaviour and gives us some idea of how much we can
trust our projections on climate change.
Also at Seamip we do socio-eeconomic scenarios, imaginging
sifferent futiures, imagining where we're all nice to each othe r or continue
as usual. Soton took part in the most recent Seamip6 .
sumaty . Ocean biology plays an important role inthe C cycle of the Earth,
but not a simple one, there are wrinkles to it. We also need to understand
how it interconnects with different parts of the Earth system.
How much C in the different parts and the balance of it all. No one of these
models is perfect , so we have lots of different models.
June we have an open day, a free day to see what we do, our doors
are open then and see the different science we do.
Q&A
The business of decline in global sea-ice year after year. An obvious feedback effect is the
albedo change from reflective ice to dark sea surface, a positive feedback effect.
Whats the effect, if any , relating to plankton growth on the bits of sea that were
always ice covered before, as I know pp can grow under thin ice.?
I've looke dat that myself. One of the things we expect to happen , as there alwys used to be
a permanent core of sea-ice that never disappeared but that part is getting
smaller each year. We expect that to disappear over the next 2 or 3 decades.
We then expect the pp to grow , with the long Arctic days in the summer,
because of the sun inclination 24 hours a day, we expect the pp to grow much
fatter there. We expect Arctic productivity to increase , at least at
first. I was interested in whether the Arctic would turn into the Atlantic ,
the New Atlantic. As it turns out its not as simple as that. We expect the Arctic to
run out of nutrient . At the moment its nutrient rich as there is no light because of the
sea-ice. The nutrient levelis high , but its not used because of the lack of light.
The ice melts, the nutrient will be consumed and then dumped in the
ocean interior via the biological pump but it won't return very
quickly.
So negative feedback?
Essentially yes. We expect the Arctic to bcome a bit like bits o fthe Atlantic
are currently, in the end. It will still be cold, every year sea-ice will
come back wintertime on the future much warmed Earth. It will be
much thinned than before . Soin the short term we expect the arctic to be more
productive , but uncertain long-term future. There is also issues
about fish will be able to live in that Arctic, and questionable sea-fishing
bonanza. Because there is stuff to eat but not all year round. Its nopt clear
whether it would transform into fully functional food-web with the kind
of species we have now. A lot of species will find it hard in the
Arctic , even if no sea-ice.
You said you exclude the effect of fish, how do you come to that decision in
general.?
The lazy approach is run your model and change it so you make the fish
important does it change your results. You tend to find some things are
more important than others and fish is just one of the unimportant.
They're playing a role at one end of the food chain , its important to
them but the bottom of the food chain does not feel what they're doing.
Complicated models that involve fish, something important there
but it doesn't add as much as you might imaging. If your interset
is fish then you absolutely can do that , that level of detail
into yhe model but our interest is the main effects that control the
bottom of the food chain . Its the nutrient ,light, space and time
for us , not the fish. Its an add-on . You can also work it backwards from
how much biomass is fish compared to other things which is much more.
Can you give us an idea of the range of predictions over say the next 2 decades,
between the most differing models?
There is quite a range, in terms of ocean productivity. Most models, on the
whole , because they make similar assumptions about how the
world works and from observational experiments , most say the
oceans will become less productive in a much warmer world.
Some models do disagree though. Temp makes a very important role
in living systems, almost a controlling role , warmer your surroundings then
typically the faster you metabolism . That makes you grow faster and some models
use that relationship with temp. But some models say the ocean becomes more productive
into the future, but the balance of opinion is that those models are probably
wrong. Its part of the attraction of having a range of models.
Even quite small signals inside an Earth system can build up. For example
for ice-ages, a prevailing view of what causes or drives ice-ages is the
relationship between the earth and the Sun and how much radiation it gets from the
sun and where that radiation falls. The changes are small but there can be feedback
systems within the Earth system , so things start piling up . You start changing temp
and before long ypu're changing cO2 which increases temp . Sometimes it
matters with the time scale your interested in . The models are well resolved geographivcally and quite expensive to run so in one of our research days we might
only simulate 5 years. Something like the Milankovich cycle that control
ice-ages , so over 10s of thousands of years, for our model would notbe possible.
There are simpler models that can do that, perhaps describing the Earth as a few boxes
an ocean and some land. Something I've been interested in is vulcanism and how
it adds silicon to the ocean and how that affects diatoms, the timescale there is
millions of years. The Eoscene period about 50my and had to run it
over 20my, small sources such as silcon and make themselves felt only over long
time periods. We try to choose a model to suit the [roblem , as we see it,
but we could always choose the wromg model. Making a simplifying assumption that
is wrong but on the whole, enough scientists and modelling groups out there ,
not all thinking the same way, will try different things.
The recently published oxygen change will that only apply to the top level?
The O2 concentration of the ocean is declining , a main reason is as the ocean
warms O2 is less soluble . The bulk of ocean O2 is coming from the air.
The deep ocean is connected to the surface by the thermo-haline circulation
and eventually the ocean is refreshed with water rich enough in O2 ,
but less O2 at the surface eventually means less in the interior.
That phenomenon has been observed, there is also second order effects .
In areas with a lot of nutrients going down rivers, you get big harmfull
blooms of pp, sinks into the ocean and sucks O2 away.
We expect O2 to decline but how far it will go , depends a lot
on the particular scenario. There is no multimodel agreement on
the O2 decline.
An example of where our models are wrong. our models are
saying thee is less than actual observations are saying.
We have a lot of ocean measuremnts of O2 but not everytwhere
and not to all depths. This is an evolving story . For animals of the
deep ocean there will be growth of anoxic regions where
they cannot live. This is what we expect but its entirely
doubtful that whole oceans will go anoxic. As well as lower concentration
of O2 in the surface as its warmer, the ocean is stratifying
as well . Warm water floats on cold water which twnds to mean
the surface becomes more and more isolated from the bottom
ocean. The overturning circulation becomes weaker and weaker.
This will also drive O2 concentrations down. Productivity on the surface
ocean , which will drop into the interior taking the O2 with it and we know O2
is replaced very slowly. In the geological distant past we know there has been
these ocean anoxic events and those are associated with mass extinction
events. I've not seen anyone stating that is what we are staring at , at the
moment. But some of the science points to similar, unlikely for the same reason.
We don't , at this time , have the answers to this either from
models or observations.
Have you modelled O2 replacement by photosynthesis?
In the model we do. When we have? production, the model concentration of
O2 increases. Much like C , its an incredibly large reservoir.
There is a lot of O2 compared to C in the atmsphere. The O2 produced by
photosynthesis is quite small , compared to this atmosphere reservoir.
In most models we consider atmos O2 to be a constant, an example of one of our simplifications. because its flux is so
slightly affected by plant production. We just say its 20%. The processes that could change it
are not large enough on reasonable time scales. The Earth had no atmos O2 at one
point , one of the worst pollution events ever was the oxygenation
of the atmos it killed off almost everything that was around at the time.
Obviously we love it now.
One thing happening on land unlike the ocean , C is good for things on land
bu tplants have difficulty getting C from the atmos. A limiting factor for them
is water, a relationship between getting C from the air and losing water thru
evaporative transpiration. Increase the CO2 in the atmos and it becomes easier to
get C from the atmos. If nothing else changes it becomes easier for
a land-plant. Currently productivity on land is increasing because of this
CO2 effect. Its offest by us cutting down trees in large parts of the world.
Thats an example where O2 fluxes would likely be larger than was in
the recent past. Even so the ratio of reservoir to changes from plant
production is so small , we tend to say we'll loose that one in the noise.
But over millions of years thats the sort of problem that would require
considering, but not for climate-change models. Its rare that we are looking
beyond 21C. But a lot of interesting stuff happens beyond 2100
, the long term fate of CO2 is an interesting thing. If you stop making CO2
tomorrow, where does it go, does it stay in the atmos, go into the oceans
or into the land. I don't think we do any modelling beeyond 2300,
concentrating on the relatively near term future. Its far enough off
for interesting thngs to be happening but not so far off that we have to
consider atmos O2.
I'm not an adherent of this because of the low of unintended consequences.
but the theory of sending rust-bucket ships around the oceans, eeding pk.
I assume that sort of thing you can feed into your models and see what is likely
to happen?
Yes, a number of people has done precisely that. Lets add iron to the ocean ,
I've done similar myself. With a student we said. Lets forget about the iron
, lets just say we could teleport C into the ocean interior , because of iron
fertilising. Put it in there at 1000m and what happens to it. So we did those
simulations and tried to see how long the C would stay there.
An interset is not just how to get C into the ocean
but keeping it there. The ocean has a long ventillation? time scale.
The ocean is always turning over, the bottom at some point in the
past was at the surface. The bottom of the ocean as at some time at the surface ,
it keeps going round and round .
The nature of the ocean is that some parts of the ocean have not seen the ocean
for maybe 2000 years. So a long time , so the idea is that if you can get stuff
int othe ocean , thats brilliant. We focused on the southern ocean , because there is lots
of nutrients there , but not much iron. So just add iron then bingo , pp bloom and
C drawn int the ocean . We skip[ped the messy details of how the iron
worked and how the C got into the ocean and ramped forward a hundred years.
A typical time span for these sort of things and we found that comparatively quickly a lot of the CO2 would come straight back out again in contact wiht the atmos , so
any benefit you thought you had, you've lost.
It can break thru the statification structure?
Yes but stratification only affects certain parts of the ocean. There is a lot of upwelling in the Southern Ocean, its my favurite bit as its so complicated. We found that about
70% of the C that got into the Southern ocean , after about 100
years it was back into the atmos. Go out to 1000 years it was a bit better.
The biological pump is a kind of accident . The way biology works, stuff grows ,
it gets eaten , it dies and usually it gets btroken down . The biological pump is the
bit thats left over, the residue than nothing has quite managed to eat, before it sank out
of the upper ocean. Biology would rather it turned into flesh or zp.
As he result , when you try such schemes as iron fertilisation , the biology is not your
friend. Its working against you. Sur eyou can get blooms , small-scale experiments
of fertilising the ocean, in iron limited areas and you can see the effect.
The result can be seen from space as a ring of green but in the end a lot got
consumed at the surface . As for solving climate change. no, there are othe r
ideas out there in the way of geo-engineering.
That was a good example of what models are for. You don't want to try something
before you've tried it in a model.
I've worked in a similar area, using geo-engineering to try to get the biological
pump to do stuff andit doesn't . It works in some qualitive way , do this, then this
happens then that happens, more C gets into the ocean but put numbers
to it , where models are useful ,you realise its not worth it.
Can there be unforseen consequences? Can you think things thru and the model
does not agree.?
Sometimes you get unforseen consequences in the models. I think in the real worls you
are likely to get different unforseen consequences. The models are simpler than the real world. We cut off some of the detail . You think you understand things
but a model can have a life of its own. Sometimes you get unforseen consequences in
your model. In the study I did, we could not make it work but
some things we've not been able to consider.
For instance what happens to O2, in the case of iron fertilisation. One idea is
add iron , cause a pp bloom , put more C into the ocean , that C consumes more
O2 which then leads to anoxic conditions which then favour the growth of
methanogens , organisms that produce methane which then gets into the
atmos and methane is a much stronger GH gas than CO2. So you've screwed syourself,
start on one path and it comes back to bite you, much worse than if you hadn;t
started. Models are quite good for showing up this. There are tool that try
to make you aware of consequences but they won;t tell you everything.
They stop at a certain level of compexity and the real world has a lot of stuff
beyond that. In the domain they do work they often can say quite powerful
things . Always incomplete, we always have caveats, that we've missed bits out.
Nevertheless we can say something interesting about how a process
will work and work into the future, what will stop happening and
what will continue happening.
Are you on the lookout for chaotic solutions, in a mathematical sense?
To me every thing is chaos. A side detail, when we do a simulation
of the present day and the future , we simulate multiple realisations
of the present day. Because we don't know anything about say 1850,
our usual start date as its about 100 years after the start of the
industrial revolution. We start as multiple versions of 1850 ,
all slightly different, to see what we can see, to sort of take advantege
of some of the chaos. Slightly more sea-ice or slightly less , slightly warmer or
colder atlantic, what difference sdoes that make , running thru to the
present day. For chaos i think of the weather system , its like a
box , the weather you have now is a ball in that box, but you don't know where
the ball will be in the box , but the box restrains limits to movement, it can only
vary tp certain amounts. When climate changes then the box changes shape
and the weather can go to different places. Often we're not interested of where the
ball is in the box , we're interested in the siize and shape of the box,
the chaotic attractor. The weather is always moving around in this chaotic
attractor and we're interested in the changing shape of that attractor.
We do factor in chaos by using an ensemble approach , multiple version of year
2000 and multipleversions of a future year and they only differ by how the
simulation was started. Once started, they see the same CO2 and the
same methane in the atmos , only differing by where they started from,
to take advantage of the chaos in the model. So if you start with a slightly
divverent condition in 1850, does that matter , if the resulta are all similar.
One of the things we've seen in our model is from 1850 to 2000
, the initial condition does matter in some parts of the Earth system .
So for the Southern Ocean , how much water is moving west to east,
is something that changes with time. So via ensembling, we could start with
the southern Ocean at different strengths. There is natural variability within
the simulation and within 1850 to 2000 it does seem to matter. But as you go to the 21C
because CC is such a strong signal , forcing the Earth system in one
direction , we find the variability between simulations gets crushed out of
them and they all start behaving the same way. I'd be interested to see
if other people's mdels also show this.
Its known, because of chaos, we cannot forecast the weather, more than about
7 days ahead.? Do you get into such problems but on a longer time scale?
There is weather and there is climate. The wether is where you are inside a box,
and climate is the changing box. We trust our models to
tell us something of the climate as a whole , but no detail of it.
We can only say something of what range of weathe ris possible in the model.
This is a way we validate our models. We don't concern ourself about whetehr
we got the temp right at this location on this day , we worry about
in that region do we get the annual seasonal pattern of temp abot right
and the extremes about right . Do we stay inside the same box or is the
box changed. There ar epeople who only work with the statistics
round such models to check they are behaving sensibly.
Weather models are different. We know what the weathe ris right now ,
place that in the model and move forward 5 days and if at that stage the model is ok, you go forward 10 days . You start getting errors in the model and they start stacking
up , and the chaos inherent in the equations of these models. Then the precise nature of
any prediction is wrong. You would not expect a model to drop to absolute zero
temp or to 1000 degrees, as it must be wrong but can be a consequence of the chaos.
Some people in the NOC are interested in some of the longer term
weather patterns , seasonal patterns are mor einfluenced by the ocean
as its an enormous rservoir of heat compared to little in the atmos. The Earth
system can extract that heat into the atmos and try to predict whethe rit
will be a hot or cold winter for instance, based on what the ocean
was doing several months before. You can view the ocean as having memory , compared to the flighty atmos. Heat comes and goes in the air but because of the specific heat
capacity of the ocean , things there can only change slowly.
W154
Tuesday 21 January 2020 Dr Robin Wilson : Monitoring the environment from space.
Hundreds of satellites orbit the Earth every day, collecting data that
is used for monitoring almost all aspects of the environment. This
talk will introduce to you the world of satellite imaging, take you
beyond the ‘pretty pictures’ to the scientific data behind them, and
show you how the data can be applied to monitor plant growth, air
pollution and more.
Of a regular picture , how do you know one bit is sky , one bit is a castle, and that bit is a tree, would do you use to work that out.
Colour is a primary way but if it was a black and white pic , you could still work out what was what. Shape or sharp lines , position and context , reflections are other possible routes.
The trees in that image and the grass are both green , why are they green. When light
shines from the sun onto the tree , in its range of colours consider as red,green and blue
, some of the red light and the blue light is absorbed by the tree, the green light
gets reflected strongly. Reflected into our eyes , so it looks green ot us.
If we split the image up into its component parts. This image recorded by a
digital camera and it records in the red green and blue parts of the spectrum
separately. So 3 separate images red green and blue. The whiter the part of such
an image , the more of that colour present. The sky is very white in the blue image,
as lots of blue ,but little blue in the grass part of the image. In the green image the
grass is lighter coloured . For such a camera , classified in terms of megapixels,
a pixel being one square dot of record. Each square has a value , a number,
representing the intensity of light in that tiny area, for that particular colour.
Seeing they are numbers, I could plot them on a graph. A graph each
of separate parts of the image, sky grass, castle and trees.
The sky has lots of blue , some green and little red. The castle is roughly
opposite, not much blue but lots of red. The tree and grass both have a
peak in the green, and lower down in the blue and red.
We can convert the colours to their wavelengths from the blue at 400nm
thru to red at about 750nm. So intensity of light vertically
on the graph and wavelength horizontal. These graph patterns
are spectral signatures, the signature of something in an image .
A number of the orbiting satellites look down, taking pics of the Earth.
Most of the ones , dealing with this talk, are in polar orbits.
Over the 2 poles and the Earth is turning under them , so over time any
one satellite passes over the whole Earth.
The longest series of Earth observation satellites is called LandSat,
running since 1972. They have all been designed to be broadly
compatible. So you should be able to look backwards and have very
similar imagery, back to 1972 and the most recent LandSat8 launched in 2013.
Landsat9 will be launched 2020 or 2021. Designed to overlap ,so there is no
missing coverage. Landsat8 has solar panels for power, computer , power units,
thrusters to move it around a bit , to change orbit and avoid potential
collisions with other space items. The main bit is basically a telescope
pointing at Earth. Zooming in, magnifying what it can see from space
and a camera much like any personal digital camera or phone camera.
So record images much like the camera pic of the castle at the start.
A Landsat image of Soton , Southampton Water, the city out to the airport,
Eastleigh and Winchester. Landsat has a spatial resolution of 30 metres.
So each pixel of the image covers 30x30m, a sort of average of what
can be seen in that area. It also has a temporal resolution , the reviit time,
of 2 weeks, a new image of every place onEarth , every 2 weeks.
Zoom into the image and you can see the pixel squares. A zoomed image of
Winchester , the red bit is the running track at the Bar End leisure centre.
An image from Sentinel2 , a newer satellite run by the Euroean Space Agency.
Higher resolution, of 10x10m on the ground and because they have 2 satellites
, spaced apart in their orbits, so data every 5 days. an image of Soton
Docks , Millbrook, Totton flyover over the Test. You can see how ships have
moved , ? of farmers fields, changes in sea-level by seeing occasionally a sandbank
or a bit of the coast comes and goes according to the state of the tide when the
image was taken.
There are higher res images, an ICANOS ? image of Eastleigh with 4m
res. There is higher res available, commercial sat imagery that is about
0.5m res. So if you lay down it can just about see you, so ethical
concerns relating to that. Zoom in on such an image and you see
cars on the M27 and the airport carpark, markings on the runway,
so quite a lot of detail. You can also go to the other extreme
4/1/51
1/19/55/30
to be continued
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