During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Because of the demise of AMSR-E the IJIS sea ice extent (SIE) numbers are no longer central to these updates. Instead I now use Cryosphere Today sea ice area (SIA) numbers and compare them to the SIA numbers in the 2005-2011 period. NSIDC has a good explanation of sea ice extent and area in their FAQ. I also look at other things like regional sea ice area, sea ice extent, temperature and weather forecasts, anything that can be of particular interest. Check out the Arctic sea ice graphs webpage for daily updated graphs, maps and live webcam images.
May 13th 2012
How depressing (image courtesy of Terrible Taxidermy). First we lost the great day-to-day extent data provided by IJIS. A couple of weeks ago ENVISAT stopped transmitting data, which means we no longer have these great radar images to check out the ice plug in Nares Strait. And since April 28th the good people over at the University of Illinois at Urbana-Champaign are having some server problems, which means their excellent Cryosphere Today page hasn't been updated since. So no daily sea ice area data either.
Apart from Larry Hamilton keeping us up-to-date every couple of days on the DMI SIE numbers, and Dr.Tskoul keeping an eye on MASIE numbers, there is nothing there to satisfy my curiosity and obsession with Arctic sea ice. And the basis on which these ASI updates are written is swept right from under my feet...
But let's stay positive, okay! At least it isn't September! And as long as we have eyes to see, we can still gaze at various graphs. So that's exactly what we're going to do in this ASI update.
The NSIDC SIE chart had SIE dropping fast, but it has leveled off again in the past week or so:
In their latest update (which I didn't cover because it wasn't telling us much we didn't know) the NSIDC had another chart showing the other years as well. It looks like 2012 has dipped below 2009 and 2010, maybe even below 2008, but still above 2007 and 2011.
Meanwhile over at DMI:
2012 SIE (30% cut-off) seems to be on top of all the other years. It's too bad they don't offer a bigger version of this chart, as the trend lines are hard to make out.
As we can see on the SIE and SIA graphs provided by Arctic ROOS the 2012 trend line is still hugging the long-term average, together with 2009 and 2010:
So everything's pretty much as it should be. The trend line could be much lower though if it weren't for a spell of anomalously cold temperatures that started about a week ago. The ice pack keeps opening up in several regions (Kara Sea, Laptev Sea, Beaufort Sea Hudson Bay) due to winds, but the water freezes over again straight away due to extra low temps. So we're still in that transition phase where melting/compacting and freezing are battling it out. Mind you, the ice is still getting thicker in large parts of the Arctic as we speak, but that will soon be over.
Here's a temperature anomaly graph showing current anomalies:
I've gotten so used to seeing green, yellow, orange and red up there in the Arctic, that it's actually quite a change to see mostly white and blue. A few days back there was much more blue all over, but I was too lazy to save the image. Still quite a lot of blue over Bering Strait, the main source of SIE and SIA decreases at the moment. Imagine what a bit of red would do to the thin ice there.
Temperatures remain anomalously high in the Barentsz/Kara region, which is also reflected in sea surface temperatures anomalies:
Also check out the animation over at DMI, to see how things are slowly, but surely heating up there. Fluctuations from day to day can be big, but in the last 30 days there has been a marked shift towards higher anomalies. So for now no let-up in the heating of the Barentsz/Kara region, which could play a crucial role in one of the WACC configurations. Looks like we're going to find out pretty soon about this potentially undeniable climate change in action.
An Arctic Dipole seems to be shaping up, keeping that transport of multi-year ice through Fram Strait going strong, and low pressure systems could finally prevent those huge polynyas in Kara and Laptev to stop from freezing over (clouds keep things warmer right now by blocking out-going radiation), but there'll be more on atmospheric patterns again in the next ASI update.
Judging from all the SIE and SIA graphs available, 2012 seems to follow a 'normal' pattern in decrease, joining the trend lines from other years, despite weather slowing things down. Next month we'll start to see whether 2012 follows the steep declines of 2007, 2010 and 2011 or whether it stays huddled up with the other trend lines.
Hopefully CT is back online again and updated every day by the time another ASI update is due. Graphs are great, but numbers are numbers.