The cod icefish re-discovered and published in 1904 by Louis Dollo. The original caption says “Mangé par le chat de l'équipage de la Terror” or “Eaten by the Terror’s cat"!
The famous polar ships HMS Erebus and HMS terror had been in the ice long before Franklin took them to their doom in the Northwest Passage. James Clark Ross took them to the Antarctic from 1839-43 on a hugely successful voyage to find the South Magnetic Pole. Ross filled in many blanks on the map and discovered and named many places including Ross Island and Mount Erebus - one of the most spectacular volcanoes yet discovered.
Ross also took civilian experts to describe and write about their discoveries. These civilians produced vast scientific volumes to record their results.
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).
"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.
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 am working on a polar oceanographic problem at the moment, but the beauty of physics is the principles are universal. That means you can end up reading widely. I came across a very interesting paper (to me):
Whilst reading the paper I quickly skimmed over the PDF to see if I was on the right track for what I was interested in. It looked good so I went back to the beginning and starting reading in more detail.
Introduction paragraph 1:
"Clipperton island got the reputation of being one of the most obscure, isolated and unpleasant places on earth"
I thought "eh?" I like a bit of unpleasantness but...
So I read on... The paragraph gives a quick history of the occupation of Clipperton Island. It was first occupied as part of the phosphate mining industry. But it doesn't have a happy history.
"In this tiny tropical hell, many became desperate to leave, convinced that the island was driving them mad. During World War I, the islanders were cut off from the mainland and died little by little from scurvy and malnutrition. The survivors, a handful of women and children, became ruled by a madman (the light keeper) who proclaimed himself “King of Clipperton”, raping whomever he wanted and murdering any who resisted. Eventually, the women killed him, putting his reign of terror to an end. By July 1917, three women and eight children were the only ones alive and were picked up by the USS “Yorktown”. Its last permanent occupation was in 1944/45 when President Roosevelt ordered the US Navy to seize the atoll. Soon after World War II ended and the atoll was abandoned"
Scurvy, malnutrition, rape and murder. I don't come across that sort of thing very often in the area of oceanography I research.
Clipperton Island is about 580 nautical miles off the coast of Mexico.
There is a very good Wikipedia page on Clipperton Island. This is quite surprising given that the atoll is only 6 km2 with a maximum elevation of 29m. It seems to be pretty regularly visited by members of the amateur radio community, and there was a private expedition there in 2013.
But I will talk about the cover. Here is a screen grab.
I think it's beautiful. I love the way the golden light reflects on the young sea ice. In fact I think it is so beautiful that we used it on the cover of a book I partially wrote and edited for my employer in 2011.
So why did I use it? To me the polar bear is in its natural habitat. The bear is wandering over decaying sea ice and refrozen melt water. Our book is filled with the science of how and why the ice grows and melts, and what adaptations and strategies the animals use to survive, plus lots of other science. The polar bear's Latin name is ursus maritimus - which in English is "sea bear": open water and ice are part of their habitat.
In a previous post I showed the temperature cycle on the Antarctic Peninsula, and pointed out that the monthly mean atmospheric temperatures show that it is actually surprisingly moderate. Whether you consider the temperature cycle moderate or not, the cold temperatures and strong winds drive an amazing amount of seasonal sea ice production.
This plot shows the average seasonal cycle of Antarctic sea ice extent against date.
The daily average extent is calculated from the satellite record from 1981-2010, and the grey shading either side of the line is the standard deviation.
Here are three obvious things to pick out of this plot.
Antarctic Sea Ice extent varies a lot: From 2.9x106 km2 in February to 18.6 x106 km2 in September. This is a range of 15.7 x106 km2.
The seasonal cycle is not symmetrical: There is a slow growth followed by a relatively rapid decay.
To really get an idea of what this asymmetric growth / decay pattern looks like watch the following you tube clip a few times. (The data for the movie is from the AMSR-E Satellite and it is from Climate Central.
So slow growth, and then rapid retreat. Ice tends to advance away from the continent, but as it retreats it can melt first within south of what you would consider the ice edge.
How the Antarctic sea ice extent is changing is for a future post, but it is currently increasing. There are significant regional changes over the duration of our satellite record. For a couple of good accesible comments on the trends in Antarctic sea extent you could read Professor John Turner in the Guardian, or Tamino on the Antarctic Sea Ice increase.
Fetterer, F., K. Knowles, W. Meier, and M. Savoie. 2002, updated daily. Sea Ice Index. Daily Sea Ice Extent Climatology. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5QJ7F7W.
In the previous post I made a plot of Antarctica and compared it to the size of Europe. I made the throwaway point that it was unreasonable to imagine Antarctica as being characterized with one climatic zone. It is not all the "coldest and windiest place" on Earth.
I thought a simple example would show what I mean:
In contrast Vostok station is quite literally an icy waste in the middle of nowhere (* but see below).
This plot shows their relative locations in relation to the South Pole.
You can see that at Adelaide Island - which is at sea level and coastal - the seasonal cycle is relatively narrow and only about 11°C. Temperatures are above 0°C in the summer.
At Vostok - which is on the East Antarctic Ice Sheet and at an altitude of about 3700m - the seasonal cycle is vast. In the Antarctic summer the temperatures are about -30°C, whereas in winter the temperatures fall and it is scarily cold (monthly mean -71.4°C in August 1966!).
If you want to know why Adelaide Island has a relatively small seasonal cycle, whereas Vostok seems to have a squashed "U" shape temperature cycle, then you have to understand something about the basic meteorology of the Antarctic Regions. (As an aside then you would understand why this happens in winter).
* - of course Vostok isn't really in the middle of "nowhere". It is over the vast and hugely significant under ice Lake Vostok, and is the location of the first great Antarctic ice core - the Vostok Ice Core.