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.
March 12th 2011
First off, I'd like to mention that I have updated the Arctic sea ice graph webpage (also thanks to the Wetterzentrale forum), which is now totalling over 30 daily updated graphs and maps of Arctic sea ice extent, area, concentration and thickness, air and sea surface temperatures, sea level pressure, and more. Let me know if you want to see even more stuff in there.
Arctic sea ice has more or less reached its maximum cover. Sure, last year the growing season was prolonged by another three weeks after this date, but those three weeks amounted to an increase of just 70-75 thousand square kilometers of thin ice. So, I think it's safe to say the growing season is over, the melting season is starting, the Arctic Sea Ice blog has finished hibernating and it's time for a first SIE (sea ice extent) update.
Extent (and area) seemed to level off about two weeks ago and reach a very early peak of 13,666,875 km2. But as nothing in the Arctic is a dead certainty, things flipped and the extent as reported by IJIS has increased some more to 13,802,344 km2 as of March 10th, with the latest peak at 13,887,188 km2 two days earlier. Is the race on? I think we'll know in a week or so. Most years in the 2005-2010 interval peaked around this time.
The current difference between 2011 and the other years is as follows:
- 2005: -267K(-13,332)
- 2006: +61K (-11,704)
- 2007: -143 (-9,894)
- 2008: -714K (-10,761)
- 2009: -356K (-10,746)
- 2010: -528K (+13,402)
Between brackets is the average daily extent rate for the month of March. 2011's average daily extent rate for March is currently 14,078 square km per day. This is bound to come down if the peak has been reached (last year shows an increase in average daily extent because the peak was on the last day of the month). 2011 is in second place, right behind 2006.
Here's the IJIS sea ice extent graph:
The Cryosphere Today sea ice area anomaly graph has consistently hovered around the minus 1 million km2 mark. It should have been going up by now, but it isn't. If it doesn't - depending on how fast the melting season gets underway - this should have a marked visual effect on Cryosphere Today's tale of the tape graph.
When it comes to CT sea ice area regions it's the Bering Sea and Barentsz Sea (I always mix those two up) that are particularly low for this time of year, probably due to anomalously high sea surface temperatures. We'll see whether there will be another spurt of growth in thise areas like last year, or whether this was it.
Here's the sea ice area anomaly graph:
Okay, that's it for now. As the melting season progresses I'll be using other relevant graphs and maps.
TIPS - Other interesting blog posts and news articles concerning the Arctic and its ice:
Patrick Lockerby is back in full swing and has written an update to his first Arctic analysis of the year: Arctic Ice March 2011 - Update #1
Artful Dodger, master of interesting links, reported in the last Open Thread that this year scientists from the U.S. Navy’s Arctic Submarine Laboratory will collect critical environmental data while riding submarines on their routine Arctic transits as part of a program known as Science Ice Expeditions (Scicex): Nuclear Subs Taking Scientists on Secret Arctic Missions
Some more on that on Navy Live, the official blog of the US Navy: ICEX is coming!
Speaking of the Navy, here's an article on The Guardian, based on a report by the National Academy of Sciences: Prepare for Arctic struggle as climate changes, US navy warned