During the melting season I'm regularly writing updates on the current sea ice extent (SIE) as reported by IJIS (a joint effort of the International Arctic Research Center and the Japan Aerospace Exploration Agency) and compare it to the sea ice extents in the period 2005-2010. NSIDC has a good explanation of what sea ice extent is in their FAQ. I also look at other things like sea ice area, concentration, volume, temperature and weather forecasts, anything that can be of particular interest. Check out the Arctic sea ice graph webpage for daily updated graphs, maps and live webcam images.
April 13th 2011
Updates on SIE are few and far between, but there's no need to wear myself out with extensive analysis until the ice starts melting out for real, come May and June. In these first two weeks of April we saw the 2011 trend line completing the triple top, but the third top didn't match the first one either, and so the SIE maximum extent still stands. It will continue to do so as the 2011 extent numbers have continued to decline slowly, but steadily.
The 2011 trend line on the IJIS graph is still in the top of the lower group of trend lines that has been joined by a fiercely dropping 2004 trend line:
The current difference between 2011 and the other years is as follows:
- 2005: +164K(-26,297)
- 2006: +463K (-26,932)
- 2007: +317K (-27,521)
- 2008: -373K (-40,240)
- 2009: -244K (-26,781)
- 2010: -455K (-40,786)
Between brackets is the average daily extent rate for the month of April. 2011's average daily extent rate for April is currently -25,781 square km per day.
Over at Cryosphere Today the flatlining of the SIA (sea ice area) numbers around minus 1 million square km has basically come to an end, with the anomaly trend line going up and settling around the minus 700K mark:
This of course is also being reflected in regional SIA numbers. The Barentsz Sea, Kara Sea, Bering Sea and Baffin/Newfoundland Sea all showed a decent uptick after an early drop. The Laptev Sea went up as well from the little fraction it had gone down towards the end of March. Mind you, some of these areas are showing drops again, especially Barents and Bering, all part of the dynamic transition phase between late ice growth and early ice break-up.
The AO is expected to go down a bit in the coming week, and this is already reflected in the ECMWF forecast for the coming 48 hours, with a high moving in from the Canadian side of the Arctic:
And this means that on the PIPS ice displacement maps we are witnessing a set-up that is slowly evolving into the fabled Arctic Dipole Anomaly. I have made a quick animation of ice displacement forecasts of the past 7 days:
Let's wait and see what this will bring. Big arrows usually mean big decreases, but it doesn't quite seem to work that way in this transition phase.
TIPS - Other blog posts and news articles concerning the Arctic and its ice:
I've inserted a RSSfeed widget that shows news articles from the past week in the right column. It's very ugly and will be rpelaced as soon as I've found something more palatable. But it functions, and that's the main thing. It partly replaces these TIPS at the end of SIE updates.
Richard Black from the BBC has an interesting blog post up reflecting some of the atmosphere on the last European Geosciences Union annual meeting in Vienna: Science and politics - a tale of two meetings