I was enjoying my polar books the other night and came across a quote attributed to everyone's favourite humanitarian polar explorer and scientist, Fridtjof Nansen.
If I were not a Norwegian, I would be an Englishman rather than belong to any other nation
In the old days Antarctica wasn’t mapped and measured by satellites like it is now. In the past it was all about exploration. Scientists were dropped at bases by ship, and then left for at least a year - sometimes two. Very occasionally more.
When winter comes the sea ice freezes up and the area of sea ice is vast. But after the winter, spring brings long days of light, and that meant travel by dog sled was possible over the ice!
To make the sled journeys more efficient food caches were left along the coast the previous summer perhaps by the same ship that left them. Then the scientists could journey easily over the frozen sea ice to the food cache, and then work inland in their area of operations.
Which brings me to these pictures. This is a food cache left by a ship (I think) in 1962 for a science team setting out from Hope Bay.
Hope Bay Food Dump
Antarctic Chocolate and meat
In Antarctica Marmite can come in tubes
Butter and meat
A tin of biscuits in an Antarctic Food Cache
Oxtail soup and a meat bar
A pile of wooden sledge boxes that contain all human needs: chocolate, biscuits, marmite, meat and soup. What more could you want?
But what about the Antarctic? The extent of the sea ice has broken records for the satellite era. (This is a very funny article making some claims about what that means - if you want a clue what is the difference between glacial ice and frozen sea water?).
Some believe the observed reduction in the Arctic sea ice volume is balanced by the increase in the Antarctic sea ice extent. So we should look at the black line in the plot above.
I will get onto why I don't think that is a good idea in a coming post.
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. ]
In 2012 I put together a storify using twitter and weblinks about the Greenland Surface Melt. In that story a bunch of climate scientists and I talked about whether the extreme melt seen in 2012 was a signature of global warming.
It is a clear and well written paper that shows using MODIS (Moderate Resolution Imaging Spectroradiometer) data from satellites that you need two things for a serious surface melt event: atmospheric blocking (which allows warm air from the south to go over Greenland) + warm surface temperatures.
The event in 2012 had both of those conditions whereas 2013 did not. The difference is striking in their Figure 1.
Their data set allows them to go back to 2000 and construct annual time series.
They find all of the features Ruth pointed out (shown in their Figure 4).
They say,
"that June-July 2007 had the most blocking days but did not have the largest melt, although 2007 has been identified as a large melt year in a seasonal sense"
The reason it did not have as much surface melt as 2012 is because the air temperatures brought over the ice sheet by the atmospheric blocking "barely reached 1.5 SDs [above the summer average temperature]". (SDs means standard deviations - basically a measure of how variable the temperature is about the mean.)
In 2012 the atmospheric blocking brought in "a long-lasting anomaly of 2–2.5 SDs [above the summer average temperature]". This is a bit bland but 2.5 SD's in this data set corresponds to temperatures ~6°C or greater above the summer average on the surface of Greenland. That is why the melt in 2012 was so large.
Häkkinen et al. (2014) make no comment in the paper about the future, or the impact of anthropogenic climate change on such events over Greenland. Looking at various assessments of the scientific literature (e.g the Arctic Report Card) we may draw our own conclusions about whether to expect more of these melting events.
It's very common to hear people harking back to the time when everything was apparently "better". Before the planet was "ruined", before anthropogenic climate change kicked in, and when everybody treated each other with respect.
Of course I don't hold that view.
Polar exploration had a golden age of sorts which is usually called the Heroic Age. It covers the time period when explorers like Mawson, Shackleton, Speirs Bruce and Scott headed South.
I am interested in the time period before that too.
The British Library have put over a million images on Flickr. With that sort of resource surely there is something polar before the Heroic age?
Searching on the term "Antarctic" throws up a vast number of results -and a couple immediately caught my eye. They were pictures drawn by one of my new favourite artists: the Scot William Gordon Burn Murdoch.
Ever since I started researching and writing about the polar regions I have always been struck by how people seem to imagine them as some sort of "untouched wilderness". This image naturally caught my eye.
I came across this brilliant Deep Sea News blog post about oil on troubled waters. It talks at length about how a surface film of oil damps out higher frequency surface waves and only the low frequency waves can propagate. The net effect is the sea feels calmer as the breaking waves are damped out.
The same thing happens in rough seas when ice forms. I took the picture below in Bellingshausen Sea.
What you are looking at is very thin slick made up of sea ice crystals in the open ocean (called grease ice). The layer of crystals only allows the low frequency waves to propagate - so you see these odd looking slowly propagating ripples.
Whilst wandering around various old textbooks I came across a wonderful quote:
Polar ice cannot be studied as other branches of science, philosophy, medicine or law are studied. The study of sea ice belongs among the most exhausting disciplines which have to be studied on the spot, in loco status nascendi et vitae, and which require strong men, absolutely sound in mind and body, courageous, willing and fit to renounce all comfort, thoroughly prepared both in theory for the work and ready to face all the hardships that may come like a bolt from the blue and in the most unfavourable moments. The sea-ice has to be studied far away, in the north or south, in white deserts of ice, where there is nothing, nothing else, no shelter no help; and where, on those vast plains in which the chasms of the sea keep tearing open and unsurmountable obstacles in the shape of mountains of ice keep piling up, the Lord only is with man.
“and as long as man will listen to the roar of the waves above the depth of the the sea, as long as the human eye will follow the play of the northern light on the silent snowy landscapes, and far away in infinite space, and so long as it will look out for the celestial bodies far away in infinite space, so long the romance of the Unknown will lead the human genius forward and upward!” (Nansen, Nebelheim.)
It is a quote from the beginning of Cryologia Maris by Josef Zukriegel, which was published in 1935 by the Geographical Institute of the Charles IV. University.
All of what Zukriegel says is all true of course - except naturally lots of women do sea ice research as well. In fact if you look at the latest AR5 IPCC report, and chapter 4 which is on the cryosphere, you will see many brilliant women polar scientists in the reference list.
Josef is a bit hard to track down for a Brit, but he does have an island named after him in Antarctica. If you look at the extremely useful gazetteer of the UK Antarctic Place names committee you can see it is actually in quite a hard place to get too.
This post is quite long but stay with it. It shows how large some of the heat exchanges going on in the polar oceans can be.
The picture above shows an iceberg through mist rising from the sea.
It is pretty, but it is also showing is a vast heat flux of hundreds of watts per m2 from the ocean to the atmosphere...
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I have talked before on this blog about how the sea ice moves, and how the International Arctic Buoy Programme provide some lovely movies of the buoy tracks which show this. I also pointed to Eric Larsen's video of the ice moving too.
But what does this ice movement mean for the climate?
As the ice moves it fractures, and the cracks extend over wide areas. These cracks are responsible for the "water sky" I talked about previously.
A recent MODIS satellite image from the Aqua satellite posted at the NASA earth Observatory shows one of these cracks (we call them leads) opening up.
From the scale bar on the bottom left you can see that the open water is ~18 km wide, and the lead is more than 100 km long. More than enough to get a ship through!
In March 2013 I was delighted to be asked to give a talk at TEDx Southampton.
This is what I talked about: What the poles are telling us about our world
It was brilliant to be asked to speak, and really enjoyed the fantastically well organized day. Many thanks to the hardworking large team who put it together, and in particularly James Dyke,Alison Simmance and Jonathan Akass.