Iceberg A68 calved from the Larsen C ice shelf earlier this year. I wrote about before.
As the berg calved it is starting to reveal a patch of seafloor that has been covered by thick glacial ice, and as the BAS press release says this has revealed:
a mysterious marine ecosystem that’s been hidden beneath an Antarctic ice shelf for up to 120,000 years.
To have the chance of making observations in an untouched environment like that is so exciting, that the British Antarctic Survey are running an expedition to investigate. You can read about it in a great piece by Victoria Gill on the BBC news site, and the brilliant Katrin Linse has done some great work with Radio 4 and the BBC Breakfast program (2hrs 20 mins in source BAS twitter account) explaining both the purpose and the work.
I was looking this morning at the recent Sentinel-1 imagery on Polarview, this is an image of A68 captured on 11 February 2018. It’s big – about 5,200 km2.
Iceberg A68 and the Larsen C Ice shelf captured from with the Sentinel-1 SAR sensor 11 February 2018.
I labelled some features in the image: the iceberg and the ice shelf are the relatively solid grey colour. The blue overlay is where land and the ice shelf roughly were (it’s called a land mask).
One thing you can see is the speckled grey colour which covers the top right hand side.
This speckled grey is sea ice.
It’s a relatively thin cover of a typically 1-3 m thick.
Antarctic Sea ice.
If you map the current sea ice distribution, and the location of iceberg A68 you can see how much sea ice they are going to have to sail through to reach the region.
Larsen C, the iceberg A68 and the sea ice extent on 11 February 2018.
There is a lot of high concentration sea ice between the ice edge and the iceberg that the ship will have to traverse. RRS James Clark Ross is a very capable ship, and she will be able to make way through the ice.
The issue is this can take a lot of time.
And time whilst ice breaking is fuel.
In open water a research ship can cover ~22 km per hour, in sea ice if you are breaking ice then maybe 5 km per hour would be good, and you probably wouldn’t break ice 24 hours per day.
They have 3 weeks.
Plus if you sail 400 km in the ice, unfavourable winds can easily compress the sea ice and trap a ship. It’s happened before, and in the modern era even capable ships get can get held up.
The satellite I used to make the image doesn’t do so well in coastal regions, so given some favourable winds there could be a nice channel for them. I am going to be watching the visible satellite imagery for that.
It’s easy to make pronouncements from 14,000 km away, but really the people on the ground will work it out.
Whatever happens I know that the researchers on board will do some great research. Plus I would be surprised if A68 moves too far from the region in the next year.
Breaking ice in Antarctica.
Breaking Antarctic sea ice on the RRS James Clark Ross.
(Apologies to the Rolling Stones for the title,
But if you try sometimes, you might find you get what you need.
*** Update 16 Feb 2028
This on twitter from Dr Stef Lhermitte
At the moment they will have to get through ~300 km of sea ice.
Being interested in the Weddell Polynya I plotted some time series data from 1 September 2017 to 23 November 2017. On the left-hand panel, you can see the see the sea ice concentration, on the right-hand panel, the anomaly of the concentration each day compared with a mean from 1989-93.
The Weddell Polynya is the low concentration region at approximately 12:00 in the movies below.
You can see the Weddell Polynya isn’t stationary.
You can also see the sea ice is still relatively low compared to the historic record. We should expect this after the extreme low sea ice from ~October 2016 onward.
Antarctic sea ice extent (with greater >15% sea ice cover) 23 November 2017. From NSIDC.
I will write some more about this next week but for interest here is the Antarctic sea ice extent anomaly for 2017.
I made these movies using the excellent Antarctic Mapping Toolbox by Chad Greene. Antarctica is the Landsat Image Mosaic Of Antarctica (LIMA), and the coastline and shelf outlines come from the BEDMAP2 data set. Sea ice data is from NSDIC.
The Amundsen Sea currently has some very large polynya. In front of the Dotson, Getz and Pine Island ice shelves they are clear in the satellite data.
The sea ice extent along the Antarctic Peninsula 9 October 2016. Data from DMSP SSMI.
A polynya is an area of open water in the winter pack ice.
These are likely latent heat polynya, and strong winds are pushing the sea ice away from the coasts to make the open water. In the open water there will be a lot of sea ice generation. I wouldn’t be surprised if the weather that is keeping the sea ice compressed against the Antarctic Peninsula is also responsible for opening them.
Taking the MODIS data from the TERRA satellite and importing that into google earth, the open water shows up as black. At the top of the image in front of Pine Island Glacier the polynya are partially obscured by cloud.
In Google Earth you can measure the area quite easily.
The MODIS imagery 9 October 2016 in the Amundsen Sea from the TERRA satellite overlain in Google Earth
These Dotson / Getz, Pine Island coastal polynyas are big!
The Dotson / Getz polynya has a perimeter ~800 km and an area ~25,500 km2.
The Pine Island polynya has a perimeter ~770 km and an area ~10,800 km2 .
The smaller polynya top left has a perimeter ~170 km and an area ~1,300 km2 .
The total polynya area is ~37,600 km2 .
It is still early spring in Antarctica and it’s still cold.
Surface temperature in °C, Antarctica 11 October 2016 from Automatic weather stations. The white box is quite close to the polynya.
With air temperatures of -15°C and ocean temperatures at ~-2°C, from my post about the sensible heat loss in the Arctic we could expect a sensible heat loss from the ocean of between 100-300 Wm-2 depending on the wind speed.
At 200 Wm-2 the sensible heat loss from the ocean in these polynya is about 7.5×1012 W.
~7500 GW.
That is a big number.
And it means this part of the Southern Ocean is losing a lot of heat. But overall it is still just a small part of the natural climate system.
There are a lot of other things going on in this region of the West Antarctic Ice Sheet, and it is a big current research focus. Dr Bethan Davies wrote an excellent Pine Island post on the importance of the region on her great website antarcticglaciers.org.
We know for example the glaciers feeding this part of the ocean have sped up.
Decline of West Antarctic Glaciers Appears Irreversible. NASA. Polynya areas approximated in the yellow boxes.
And this has caused led to many changes in the West Antarctic Ice Sheet interior. For example Prof Mauri Pelto wrote a great blog post about the retreat of the Smith Glacier which feeds the Dotson Ice Shelf. It is also an area where a while ago I wrote in Recent Amundsen Sea Embayment Research, about the very interesting hydrology beneath this part of the West Antarctic Ice Sheet.
On my list of things to do is see how long these polynya have existed for.
[This is a post bringing together things I have done elsewhere whilst learning how to use this platform.]
Back in July 2012 the global news media went very big on a story on the Melting of Greenland.
The original BBC Greenland Melting story
I got involved in a discussion on twitter about it, with lots of context and decided to have a go at seeing if I could put together a “storyify” on it using the contributions of a wide range of outstanding climate scientists.
That was fun, and quite popular and is here:
On 25 July the media went big on a satellite measurement showing 97% of the surface of Greenland showed the signature you would expect from melt, in July. I understand there are many ways to tell this story, but this is the way I saw it develop from the perspective of a polar oceanographer.
Storified by Mark Brandon · Thu, Jul 26 2012 05:17:18
Greenland’s massive ice sheet has melted over an unusually large area this summer, Nasa says, describing it as a… http://bbc.in/PhjjQ1BBC SCIENCE So this is the original story posted at dawn UK time. The original press release was published 24 July 2012 Satellites See Unprecedented Greenland Ice Sheet Surface Melt – NASA ScienceSatellites See Unprecedented Greenland Ice Sheet Surface Melt July 24, 2012: For several days this month, Greenland’s surface ice cover m… So I tweeted that story – but I thought that surface melt isn’t just the real story. That was the paper published in PNAS yesterday linked with this. Greenland surface melt story: Paper in PNAS this week shows last year was heavy melt too & it did affect ice mass http://bit.ly/MGoLxNMark Brandon That was the paper published in PNAS on Tuesday 24 July and is “Open Access”. If there is ever a need for yet another “open access is brilliant” statement, it is here. Bedrock displacements in Greenland manifest ice mass variations, climate cycles and climate changeEdited by David T. Sandwell, Scripps Institution of Oceanography, La Jolla, CA, and approved June 11, 2012 (received for review March 19,… What this paper shows is that there is they have found a link between surface melt and bedrock displacement. This implies a link to ice mass.So bed mass displaces upwards implies that there is a reduction in ice on the land. Unfortunately I got the year wrong. It was actually a year earlier and 2010, not 2011. So I tweeted that. doh – it was 2010 not 2011 for greenland melt – but implication is last year wld be expected increased loss too. #ineedsomecoffeeMark Brandon But given last 2011 surface melt data: 2011 Greenland Melt Season : Image of the DayExcept for the edges, Greenland is buried in ice year round. Each winter, snowfall covers even the margin, leaving the entire island whit… which was above the long term average (but less than 2010), we could expect a similar result to that demonstrated in the PNAS paper. So I tweeted it and made the link explicit. Widespread surface Melting on Greenland http://1.usa.gov/MGpK0T is linked to ice mass loss & so sea level http://bit.ly/MGoLxNMark Brandon Then I made a link to the fact that the sea ice is at a low. Sure there are weather patterns going on here but there is a background of a long term trend put greenland surrface melt & arctic sea ice tracking at low level http://bit.ly/LLIwCH clear evidence of arctic amplification? Tundra nextMark Brandon I thought about it a bit more and Jason Box ( @climate_ice ) has been working for a long time in Greenland – I have been listening to him for a long time through publications and conference presentations he has given. He published something on his blog in January 2012, which showed this was going to happen. Meltfactor.org ” Blog Archive ” Greenland Ice Sheet Getting DarkerFreshly fallen snow under clear skies reflects 84% (albedo= 0.84) of the sunlight falling on it (Konzelmann and Ohmura, 1995). This refle… So the ice is getting darker, and he said “This decline is not only over the lowest elevations, but occurs high on the ice sheet where melting is limited.”
If the ice is getting darker then it will absorb more solar radiation.
In June 2012 @climate_ice posted Meltfactor.org ” Blog Archive ” Greenland ice sheet reflectivity at record low, particularly at high elevationsAn updated compilation of NASA MODIS observations of Greenland ice surface reflectivity through 22 June, 2012 indicates that now, well in… For me the clearest statement is:
“Perhaps most remarkable about the 2012 pattern is how much darker the snow and ice is becoming, not only at the lowest elevations around the ice sheet periphery where melting is always most intese, but in the higher elevation net snow accumulation area.”
but the context is as he said “It’s not a runaway loop, just an amplifier. A record setting melt season is likely if this pattern keeps up this year.” He was unsurprisingly correct. Plus there was clearly something “odd” going on with the weather.
So I tweeted that.
In Jan 2012 @climate_ice – Greenland Ice Sheet is Getting Darker http://bit.ly/ywMyEA in June he wrote http://bit.ly/LMwVAtMark Brandon So the observation is what Jason Box (and I) would expect!, and something many saw coming.
But then it got more interesting. Marcus Brigstocke saw the Grauniad piece on the story.
(Marcus is one of the few standup comedians who has brave enough to takle climate change and AGW http://www.marcusbrigstocke.com/biog.php )
RT @guardianscience: Greenland ice sheet melted at unprecedented rate http://gu.com/p/3997d/tf MB Erm… Ok? Everyone ok? With this? Ok then…Marcus Brigstocke Dr Tamsin Edwards (Bristol University), Dr Ruth Mottram (Danish Meteorological Institute) and myself tried to help him with an explanation. @marcusbrig Agree disconcerting… but 1 event is weather…of course if it reoccurs it’s climate — Tamsin (climate / sea level scientist)Tamsin Edwards @flimsin @marcusbrig interestingly, 2002 had almost as wide a melt extent (briefly) but 2007, 2010 and poss 2011 bigger in total melt termsRuth Mottram @ruth_mottram @flimsin @marcusbrig plus PNAS paper linking surface melt-> mass loss http://bit.ly/MGoLxNMark Brandon So Marcus clearly got the message that it could not be particularly striking.
But being interested in getting it right I guess, Marcus asked if we were OK with the measurement. @icey_mark @ruth_mottram @flimsin Scare mongering aside (as if that were possible) how concerned are you by this news? A blip or a warning?Marcus Brigstocke @marcusbrig @icey_mark @ruth_mottram I think consensus is: watch & wait. Once is weather. But if it happens again, it’s the sign of a shift.Tamsin Edwards @marcusbrig @ruth_mottram @flimsin from me not a surprise. This in Jan 12 http://www.meltfactor.org/blog/?p=453 this is result. It supports other evidenceMark Brandon @marcusbrig @ruth_mottram @flimsin A striking measurement that supports what could be expected – but I agree with Tamsin!Mark Brandon @marcusbrig @ruth_mottram @flimsin I dont understand how some join dots if evidence against – but hysteria at a measurement supportingMark Brandon @flimsin @marcusbrig @icey_mark I agree too, lots of changes measured but records too short. Makes it easier to melt faster in future thoughRuth Mottram @flimsin @marcusbrig @icey_mark And depends on rest of summer and snow this winter (several low precip winters last few years contribute tooRuth Mottram Leo Hickman (Guardian journalist) noted: @flimsin @marcusbrig @icey_mark @ruth_mottram “Watch and wait” – seems to sum up climate policy, tooLeo Hickman @leohickman @marcusbrig @icey_mark @ruth_mottram that’s a different questionTamsin Edwards @flimsin @marcusbrig @icey_mark @ruth_mottram Sure. But there does seem to be an awful lot of “watch and wait” in climate discourse :-(Leo Hickman There’s clearly a long way to go in that discussion, and by other experienced colleagues as well. I look forward to their “storifys!
But Leo then asked an awesome and obvious question. How long before we can tell whether it is a climate signal or just a weather event?
@flimsin @marcusbrig @icey_mark @ruth_mottram Serious Q, tho: how long do u wait before u lose the ‘weather’ caveat? Climate=30yrs, no?Leo Hickman I tried to pull a couple more people I could think of off the top of my head who have engaged lots in the past, but also missed some excellent people who also contributed. @leohickman @flimsin @marcusbrig @ruth_mottram I would ask @richardabetts, @dougmcneall and @markpmcc + Tamsin. They see furtherMark Brandon Luckily some of them decided to “play” and get stuck in. @leohickman @flimsin @marcusbrig @icey_mark 30 yrs standard, but largely due to convenience when standard agreed – there was 30 yrs of dataRuth Mottram @leohickman @marcusbrig @icey_mark @ruth_mottram Yes, so 1 event in 30 is weather… but 5 events in 35 years might be climate.Tamsin Edwards So Both Ruth and Tamsin are saying you need a longer time period, but it is the frequency of the “extreme” events which is important too. This is not new stuff and we have seen this sort of discussion for many climate events such as hurricanes, and droughts.
But both of them point out that it is complicated and probably worth more than 140 characters.
@leohickman @marcusbrig @icey_mark @ruth_mottram So it really depends which aspect of the system you are looking at. e.g. can’t say:Tamsin Edwards @leohickman @marcusbrig @icey_mark @ruth_mottram “extreme weather increasing”: depends if extreme heat (up), cold (down), hurricanes (dunno)Tamsin Edwards @leohickman @flimsin @marcusbrig @icey_mark prob depends on what you’re measuring and if rare events, palaeo important too ask @ed_hawkinsRuth Mottram Then ace climate modeller Doug McNeal (Climate scientist and statistician at the Met Office Hadley Centre) said. @leohickman @flimsin @marcusbrig @icey_mark @ruth_mottram This is an *interesting* question…*system running*… a) it depends.Doug McNeall He is not being difficult here – he is being good. You really have to define the question carefully in the Earth system. At one level it is trivial. Increase the temp of the planet by say 10C, there will prob be no ice on greenland in 5000 years. But what we are asking is about rates of change. This really is hard – but vital to understand if you want to plan for example sea level defences.
Leo (quite rightly) asked about a specific guideline for the date we can expect to “know”.
@flimsin @marcusbrig @icey_mark @ruth_mottram Thnx. So when is Year 1 in this case (Greenland)? When will the 30 years be up so we can know?Leo Hickman I pointed out that this is probably not year one, @leohickman @flimsin @marcusbrig @ruth_mottram It’s not year one. http://svs.gsfc.nasa.gov/vis/a000000/a003700/a003720/index.html As ruth said the trend is there…..Mark Brandon SVS Animation 3720 – Annual Gradient Melt over Greenland 1979 Through 2009NASA GSFC Scientific Visualization Studio And remember Ruth had already said (repeated here) @flimsin @marcusbrig interestingly, 2002 had almost as wide a melt extent (briefly) but 2007, 2010 and poss 2011 bigger in total melt termsRuth Mottram So it is almost certain this is not year “1”.
Given the climate signals in the rest of the Arctic e.g the clear downward trend of Arctic sea ice extent, e.g
ftp://rocky.umeoce.maine.edu/users/apalacz/bilbiography/Comiso08.pdf
or a slightly longer term view http://www.nature.com/nature/journal/v479/n7374/full/nature10581.html
The fact that “The Arctic is warming two to four times faster than the global average” http://www.agu.org/pubs/crossref/2012/2012GL051598.shtml
And so on.
The question is “how much are humans responsible for”. This is a serious mathematical challenge but it can and is being studied with some very interesting success. Mark McCarthy (UK Met Office) said:
@icey_mark @ruth_mottram @dougmcneall @leohickman @flimsin @marcusbrig we get around weath-climate issue with fraction attributable risk estMark McCarthy What he means here is you can estimate the fraction of the melt attributable to humans – and it has been done here: @leohickman @icey_mark @ruth_mottram @dougmcneall @flimsin @marcusbrig some context and examples here.. http://www1.ncdc.noaa.gov/pub/data/cmb/bams-sotc/2011-peterson-et-al.pdfMark McCarthy It’s a heavy read for the non-scientist but it shows ways you can estimate what “we” are responsible for. Unfortunately to Doug’s knowledge no-one is doing it for Greenland yet. But it maybe someone is. @leohickman @icey_mark @ruth_mottram @dougmcneall @flimsin @marcusbrig last tweet example of method but has not been done for Greenland ice.Mark McCarthy Ed Hawkins (Climate scientist at University of Reading) runs an excellent www site called the Climate Lab Book. (He has been encouraging other scientists to contribute to it). Climate Lab Book | Experimenting in open climate science – open for contributionsThe time at which the signal of climate change emerges from the ‘noise’ of natural climate variability (Time of Emergence, ToE) is a key … Well Ed pointed out that the more variable a signal is, then the longer it takes for a signal to emerge. @leohickman @ruth_mottram Depends on amplitude of variability which determines when ‘signal’ emerges from ‘noise’. e.g. http://www.climate-lab-book.ac.uk/2011/time-of-emergence/Ed Hawkins What he means is: if the temperature of London, UK in December is consistently 10-11C for 30 years and then for the last 2 years it jumps to 15-16C you can be pretty sure the signal has changed. (This is not the same as who is responsible for the signal change!). But if the temperature of London, UK in December is consistently 10-15C for the last 30 years, and then for the last 2 years it changes to 11-16C, then you have a harder time suggesting the signal has changed.
Broadly speaking this is exactly what Tamsin, Ruth and I were saying to Marcus above.
Doug put that explicitly.
@leohickman So the number of years needed to determine ‘climate’ depends on which part of that distribution you are looking at.Doug McNeall But the point remains: It can be done. Gareth Jones (Who I think is also at the UKMO but no doubt he will correct me!) gave another example in the scientific literature. @leohickman @flimsin @marcusbrig @icey_mark @ruth_mottram This study discusses the challenges of climate attribution http://www.image.ucar.edu/idag/Papers/stott_regional_perspective.pdfGareth S Jones John Kennedy also pointed at a world meteorological organization paper which describes the method. @dougmcneall @leohickman Blair Trewin wrote WMO note on climate normals. It depends on the variable & intended purpose. http://www.wmo.int/pages/prog/wcp/wcdmp/documents/WCDMPNo61.pdfJohn Kennedy And Today 26 July there is an brilliant example by @jonny_day which is published in Environmental Research Letters has a striking result. Loss of Arctic sea ice ‘70% man-made’http://gu.com/p/39a39By @jonny_day, formerly at Bristol. See also http://julesandjames.blogspot.co.uk/2012/07/loss-of-arctic-sea-ice-70-man-made.html by @jamesannanTamsin Edwards This is an open access paper too and worth visiting for the video abstract. Nice work Jonny. Sources of multi-decadal variability in Arctic sea ice extent – Abstract – Environmental Research Letters – IOPscienceThe observed dramatic decrease in September sea ice extent (SIE) has been widely discussed in the scientific literature. Though there is … I leave the last word to Ed @leohickman @dougmcneall Ask N climate scientists a ‘simple’ question. Get N different less simple answers!Ed Hawkins I don’t take this in a negative way – what he is saying (IMO) is that tying down the question is very important.
Thanks to all the contributers.
POSTSCRIPT: Next day
(or it doesn’t matter how hard you try….) Terrifying: massive ice melt across Greenland. Worse & faster than anyone imagined. http://www.guardian.co.uk/environment/2012/jul/24/greenland-ice-sheet-thaw-nasa #climatechangeGeorgeMonbiot This is what climate change looks likeAn epic struggle for the future of our world is unfolding in the Arctic, as oil giant Shell is ready to swoop and begin drilling the land… And inevitably that is the fault of the scientists.
Bad bad media people who use scientists!
the ‘headline’ have gone around the world.. job done.. scientists used. @ed_hawkins @icey_markBarry Woods But finally I would like to make the point that press & comms officers who work in the organisations I have worked in and had dealings with have IMO been both brilliant and constructive.
The fact is they don’t want to get it wrong either.
The reaction was surprising and very positive. The science story ended up with almost 3,000 views (so far) and was described by probably my favourite science journalist as “bloody excellent“.
My conclusion? You can tell complex scientific and environmental stories using storify.
The polynya I saw forming in early February is still clear, and very large in the Southern Weddell Sea. At the moment it is more than than 80,000 km2, although there is clearly a lot of young sea ice covering a large part of the polynya.
The Weddell Sea 5 March 2017 in the Terra MODIS true colour image.
In my original post I said this was likely formed by winds from the Ronne Ice Shelf.
Well Dr Stef Lhermitte (Delft) has put together the most amazing movie showing the development of the polynya over January and February. It shows satellite sea ice data with winds from the ECMWF overlain.
You can clearly see the winds pushing the sea ice away from the ice shelf as time progresses.
It is just as @StefLhermitte said in his tweet yesterday:
Tweet from StefLhermitte
One really nice thing that I had seen but didn’t mention as it didn’t fit easily in the original post, and that is the grounded iceberg Stef highlights.
This is iceberg A23a, which is ~3,800 km2!
A23 was formed in August 1986 from the Filchner Ice Shelf Front, and at formation it had an area of ~3,850 km2, and was ~5-600 m thick (Grosfeld et al, 2001). So in 31 years it has only moved ~200 km mainly because it has been (and currently is) grounded (that is stuck on the sea floor). In that time it has lost ~50 km2 of its area.
You can download from Polarview, a Sentinel-1 SAR image that was aquired on 6 March 2017 (01:01:06). I’ve labelled it so you can see the A23a.
From PolarView: Sentinel-1 SAR imagery acquired: 06-03-2017 01:01:06.
A23a is about 75% the size the iceberg that will soon break from Larsen C, although I would be surprised if that coming iceberg will last as long as this one because it is so much further north and closer to the open ocean.
You can see very clearly in the Terra MODIS imagery from 5th March that A23a a fracture is developing across the iceberg.
Iceberg A23a in Terra MODIS imagery 5th March 2017.
It is undeniably vast and the broadcaster Matt Teller posted this over a year ago.
The Antarctic summer is ending now and although this year is clearly unusual in the satellite record, we should expect the polynya to freeze over as winter develops.
Antarctic sea ice extent (with greater >15% sea ice cover) 7 March 2017. From NSIDC.
I would expect A32a to be around for many more years.
This is the 2012 sea ice extent for both the Arctic and the Antarctic. The day of year and the calendar day are at the bottom.
I chose 2012 only because it is the most recent complete year in this data set.
My reason for making this video is because there have been a couple of huge news stories recently about the West Antarctic Ice Sheet:
On 12 May 2014 we heard that for all intents and purposes the West Antarctic Ice sheet is doomed (here is the primary research which is open access).
Then on 19 May 2014 we were told that Cryosat observations had shown that the loss of ice from Antarctica had increased quite a lot (here is the primary research).
For excellent commentary on these stories you can visit Carbon Brief, or Antarctic glaciers.org.
But whenever there is a big story about the decay of the West Antarctic Ice Sheet – which remember is land based glacial ice, some instantly point to this being not important because sea ice in Antarctica has been at record levels.
People who suggest that the observed decrease in glacial ice is somehow balanced by the observed increase in Antarctic sea ice extent are wrong. The sea ice is generally only a couple of metres thick and it is telling us quite a different climate story.
Over the next few posts I will try and explain why the decrease of Arctic sea ice is not balanced by an increase in Antarctic sea ice extent, and why there is no contradiction in glacial ice at the edge of the Antarctic continent decaying whilst simultaneously the sea ice is at record extent.
[If anyone want the clip, also the Arctic and Antarctic as separate files in various large sizes and formats just send me an email at my work address – you will find a link on the “About me” page. And I will send you a dropbox link. I am a big fan of Creative Commons and Open Educational Resources. ]
–
The data is from the US Defense Meteorological Satellite Program (DMSP), and the data is freely accessible from the National Snow and Ice data Centre.
The MODIS sensor satellite imagery is showing a beautiful and evolving large plankton bloom in the Chukchi Sea at the moment.
Plankton bloom in the Chukchi Sea, as seen in the MODIS sensor on 23 June 2015. Alaska is on the LEFT and Russia the RIGHT. The image is looking SOUTH.
The plankton are the lighter green bands I’ve labelled and the full image is available at an astonishing 250m resolution.
If the Bering Straight looks odd it’s because this image is taken from over the North Pole and looking southwards.
Screengrab from Google Earth Showing North and the direction of the satellite view. Alaska is on the RIGHT, Russia is on the LEFT.
Conventional wisdom says that as the Arctic Ocean sea ice retreats over the coming decades and the ocean warms, then we are going to see more plankton blooms like the one shown above.
But that’s not the whole story. Professor Kevin Arrigo published a paper in 2014 that suggested the plankton blooms in this part of the Arctic can form under the ice.
Abstract of the paper. The journal page is here, and you can download the PDF of the paper.
He and his co-authors suggest that melt ponds on the sea ice let enough light through to spur the bloom on. The NASA image below from the Wikipedia page on melt ponds tell the story.
Melt ponds on sea ice in the Arctic. Snow has been melted away to form pools which can let through light. Source.
The dark areas are ponds of water where the snow has been melted away. The bare ice beneath can let light through. Arrigo and his co-workers suggested that this is enough for biological production.
It was also the subject of a post I wrote a couple of years ago.
Jonathan Amos reported on a piece of work last year that showed the extent of the melt ponds can also predict the summer extent of Arctic Sea ice.
We should expect more more plankton blooms as the Arctic changes. You can learn more about the Chukchi Sea at the Chukchi Sea Environmental Studies Program (CSESP).
The summer of 2016 saw the joint second lowest Arctic sea ice extent. But in the middle of October unusual Arctic weather has led to it becoming the lowest extent. At the same time, Antarctic sea ice extent has also reached record lows. Tamino has a simple and clear post about what a surprising thing this is.
The Northern Hemisphere Sea Ice extent from Tamino’s blog “Open Mind”. The current year 2016 is in Red
Why is it so low?
The plot below shows the mean November Arctic sea ice extent, the sea ice extent on 16 November 2016, and the difference between the extents from 1993 to 2016. Regions shaded at the top end of the scale (the red colours) mean there is less ice now compared with in 1993.
The mean Arctic sea ice extent in November 1993, the daily sea ice extent on 16 November 2016, and the difference between them.
The stand out region (to me!) is North Russia where the Kara Sea is almost entirely clear, followed by Hudson Bay, Baffin Bay, East Greenland and the edge of the Chukchi Sea. I was interested in what was going on in the Kara Sea so I made a movie of the sea ice extent from 1 November 2016 to 16 November 2016.
Arctic sea ice 1 to 16 November 2016.
The striking thing in the clip for November 2016 is that the sea ice extent has actually reduced in the Kara Sea!
The sea ice extent in Chukchi Sea is increasing, but very slowly – and you can see from my previous image that it is very low compared with 1993.
Clearly the Arctic is experiencing strange conditions at the moment. On the climatereanalyzer.org website you can see the 5-day forecast from 17 November 2016 (tomorrow).
The temperature departure from average is off the scale over the Arctic Ocean. It’s much colder over Russia.
The 5 day forecast from 17 November 2016 from ClimateReanalyzer.org.
These are astonishing observations. When the winds change and the cold air currently over Russia ends up over the ocean I would expect it to freeze up rapidly (once the surface layers have cooled). But starting so late in the year the sea ice could end up thin enough for something impressive in the near future.
I made a gif of the full current Arctic growing season up to 16 November 2016.
I have already written a little about the this years Antarctic sea ice extent in the Antarctic Peninsula sea ice late winter 2016, in The Western Weddell Sea ice factory, in The development of the Amundsen Sea Polynya, in Dotson Getz Polynya ice growth, and in The Prince Gustav Channel is opening.
For interest, I chose November 1993 for comparison for two reasons, first it’s just before the big Arctic sea decline, and secondly I was in the Arctic for 4 months that year doing my PhD research.
Tamino is noting that the global sea ice is “About 6.9 standard deviations below the 1981-2010 mean.” . Amazing times.
A recent interaction with a scientist left me both bemused, and if I am honest a little bruised. He described twitter as “that rather infantile social network system.”
Co-incidently Peter Gibbs, an ex-Antarctican, BBC broadcaster and weather forecaster asked me about media work as a scientist – but given my recent interactions I flunked the exam by not answering his question. Sorry Peter. What I did do was write something quickly on why I like twitter.
Here it is for posterity.
The TL; DR answer is personally I think twitter is good for science, scientists, and for most people really.
Summary
I cannot sit on the fence. I like twitter and what it offers. I have learned things I never would, built genuine relationships with international people who I would have perhaps have only met over a quick coffee at a conference. And I have changed the way I speak about science.
It is interesting, and often funny.
It can of course be a harsh and challenging space. I am genuinely horrified at what I have seen some colleagues endure online – particularly the women: but it is here to stay. I wish my female colleagues and women in general were always treated well, and as people, but the only thing I can personally do is contribute to a positive space. I believe twitter is a strong positive for science, and it is a worthwhile investment of your time.
This short document has a few ill-considered ideas about what I like about it.
1) Connecting
Twitter enables you to connect with other scientists and researchers across disciplines and fields. This is becoming more and more important. We can all easily be experts in our own specialism – in fact it is expected. But whenever we talk to our family, the public, other researchers or the media they want and need to know what our work means in a wider sense. Twitter quickly enables you to build a wide network of people with related interests, and if you do not know something you can ask easily.
Trivial example? Want to know the best palaeoclimate record of an area you are interested in? Ask the paleo scientists directly on twitter and if time zones match you will get an answer pretty quickly.
You can also build relationships with colleagues from other departments, universities and countries. Imagine it as being like working in an open plan office but without the draw backs. Have colleagues in a different university? Just casually keep a conversation going through twitter. In 3 years I have built excellent relationships with many people who I professionally respect, and would love to work with – but without twitter I doubt I would have “met” them.
2) Many eyes make light work
If you are interested in a particular area of science and you have built a network whether to listen or to participate in, instead of one set of eyes trying to pick out things of interest and relevance to your work, you have many. You will find more research, more related media and more that is of interest and relevance to you and your work.
3) You can visit conferences virtually
There are a lot of science meetings going on. In fact it is impossible to attend a tenth of the things you would like to. But with twitter and a hash tag you can listen to a conference virtually. For example, in September 2014 I was the co-organiser of a 4 day meeting at the Royal Society. Over the 4 days of the meeting with the hash tag #RSArctic14, there were ~2600 tweets, and it reached over 340k people online. The hash tag and tweets were contributed to all over the world (the metrics are easily traceable), and we can even break it down it 69% of the contributors to the hash tag were male, and 31% women. Twitter turned what could have been nationally important science meeting into an internationally relevant one.
4) You can crowd source individual conference talks or news events
There are tools like storify which enable you to build stories about conference talks and news events using twitter. If you use these easy tools you can build science stories about key news issues. I offer you three examples:
The first is a talk that was at the Royal Society. It has had ~600 views, and tells the story of a view of the potential for Arctic methane clathrate affecting our climate.
A storify of a research talk.
The second is about melting on the Greenland ice sheet and has over 3000 views. This latter one led to me being invited on Radio 4 and news interviews as I clearly (in someone’s view!) knew what was going on.
A storify of a news story
And finally a storify of a House of commons Science and Technology committee I – and others – listened to online about the possible merger of the British Antarctic Survey and the National Oceanography Centre.
Storify of the possible merger of BAS and NOC
You can tell complex stories with twitter, and change the ephemeral nature.
5) On the whole twitter is a positive space
We all hear horror stories of how terrible online space can be and how negative it is, but in my experience that is a small component. If you tweet something like “I am giving an interview to XXXX” then I would bet virtually all of the responses you would get would be along the line of “you will be brilliant and enjoy it”. OK so some people may think you will be terrible – but even if they do think that, then they very rarely say it.
That means it feels a positive space and our online colleagues are in my experience very supportive. If you are a climate scientist you could get something along the lines of “are you going to talk about the co2 scam?” or the “pause”, or “global warming isn’t happening”, but those can sometimes be worthy questions, and part of a scientist’s role is talking to people who ask questions. I have to say l have had many questions that initially I thought were just people attacking me, but with a bit of thought I have learned a lot from the answers to them, and perhaps more importantly why they were asking them.
It is worth noting that if you behave horribly online, then you will get that back. If you behave politely and fairly then it is, in my experience, a good space.
6) You have to be prepared to stand by what you say
I have had an experience very recently when a scientist at a UK university complained to my management and just about everyone senior in science he could list through registered post that I had likely “defamed” him online. He issued me and my university with clear and specific legal threats. This was personally a bad experience as I have never encountered such bizarre legal threats before. You can find the story online if you are interested and see if you feel it warranted a pseudo legal attack, but the complaint was found to be without merit.
Now I think the reason the person attacked me and some colleagues with the threats is because we passed comments on what he was saying in public. And when we did using our professional expertise and fair comment he called “foul”. In my experience some people think that science communication is a one way broadcast action with no communication. You do see this behaviour on twitter as well.
But this is not how it works.
For example if I say “Antarctica is melting”, I should expect clever people on twitter to point out to me at a minimum that 1) Antarctic sea ice has been at a record maximum this year so what on earth do I mean, 2) to ask questions about which bits are melting? and, 3) to ask if there is an anthropogenic cause.
So you need to think about what you are saying as you are leaving digital footprints. Expect to be asked what you could perceive as critical questions. But in fact that is good – because it demonstrates people are interested in what you say, and you can sharpen both your ideas, and how you communicate them.
7) Introvert / extravert?
I would say I am an introvert. I could go as far as saying I am not a very sociable person. In my experience twitter is the perfect way for an introvert to connect with people. It is basically trivial, you have such short messages – so you cannot give much away, and you get to choose when to interact. It is, in my view, the perfect social space for anti-social people.
8) Contribute to web space and give something back
Have you ever used Google or Wikipedia to find out something work related? Of course! So give something back and be a net contributor the space. So you find something such as a journal article you are interested in, then tweet it with some context for your followers (I personally prefer “listeners” rather than “followers” because the latter implies a dynamic which does not exist). If you, and some of your network do that then there will be a lot of useful links and information for the lay person and colleagues in your subject area. You should also contribute to a Wikipedia article. Then at least you will know it is right!
All these things give you the status of someone who people may think actually knows something. (But remember my point 6 above).
Journalists and the public will ask you questions and you will get requests to be interviewed.
Overall my top tip is make it your mission to add something of value, whether it’s a link to an article you like with comment, or something you have just written. Make the space something you enjoy.
9) You can have fun
Twitter can be funny. You can come across many things that make you laugh, and you can always find things you are interested in but are off your radar. In addition you can interact with people you never would or indeed could.
I have had tweets of mine read out on Radio 5 about what logs are used for in mathematics, I have talked to women’s hour about statistics(!), And as another example: saw a television program last night on Pompey hosted by Professor Mary Beard and you have a burning question about it? Ask her on twitter. In my experience it’s very likely you will get an answer both from the Prof, and from others. Just yesterday I had a great interaction with the makers of the Wonders of the Monsoon about how they made their series. The producers and film makers were wonderfully generous and only too delighted to share their expertise. Most people are. We don’t want to work in silence do we?
Summary
You should be able to tell, by and by, I like twitter. Happy to talk science if your interested – particularly if it’s something polar. You should get online and contribute, enjoy and exploit the space too.
Resources
From the American Geophysical Union we have Building an Effective Social Media Strategy for Science Programs by Wendy Bohon et al and published in EOS.
From Holly Bik and Miriam Goldstein we have An Introduction to Social Media for Scientists published in PLOS Biology
From Darling et al we have The role of Twitter in the life cycle of a scientific publication published in the Peerj.
From Letierce et al Understanding how Twitter is used to spread scientific messages.
From the LSE and Mollett et al Using Twitter in university research, teaching and impact activities.
And finally from Vitae Innovate a Handbook of social media for researchers and supervisors.
If you get this far please feel free to post additional useful resources in the comments. Thanks.
ADDED 31OCTOBER 2014
I asked about additional resources.
So from Prof John Butterworth (author of this magnificent book Smashing Physics) we have a really excellent 10 minute video
From Prof Simon Leather we have a great article via Barnaby Smith: Why I Joined the Twitterati: Blogs, Tweets & Talks – Making Entomology Visible.
And from Alex Brown a great article Twitter is the conference pub.
Iceberg A68 and the Larsen C Ice shelf captured from with the Sentinel-1 SAR sensor 11 February 2018.
Antarctic Sea ice.
Larsen C, the iceberg A68 and the sea ice extent on 11 February 2018.
Breaking Antarctic sea ice on the RRS James Clark Ross.
Antarctic sea ice extent (with greater >15% sea ice cover) 23 November 2017. From NSIDC.
The sea ice extent along the Antarctic Peninsula 9 October 2016. Data from DMSP SSMI.
The MODIS imagery 9 October 2016 in the Amundsen Sea from the TERRA satellite overlain in Google Earth
Surface temperature in °C, Antarctica 11 October 2016 from Automatic weather stations. The white box is quite close to the polynya.
The Weddell Sea 5 March 2017 in the Terra MODIS true colour image.
Plankton bloom in the Chukchi Sea, as seen in the MODIS sensor on 23 June 2015. Alaska is on the LEFT and Russia the RIGHT. The image is looking SOUTH.
Screengrab from Google Earth Showing North and the direction of the satellite view. Alaska is on the RIGHT, Russia is on the LEFT.
Abstract of the paper. The journal page is here, and you can download the PDF of the paper.
Melt ponds on sea ice in the Arctic. Snow has been melted away to form pools which can let through light. Source.
The Northern Hemisphere Sea Ice extent from Tamino’s blog “Open Mind”. The current year 2016 is in Red
The mean Arctic sea ice extent in November 1993, the daily sea ice extent on 16 November 2016, and the difference between them.
The 5 day forecast from 17 November 2016 from ClimateReanalyzer.org.
A storify of a research talk.
A storify of a news story
Storify of the possible merger of BAS and NOC