Arctic Sea Ice

NSIDC Arctic sea ice news April 2011

NSIDC has just released its April analysis. Some interesting tidbits:

Arctic sea ice declined slowly through most of April. Because of the slow decline in April, ice extent for the month as a whole did not approach record lows, as it did in March. However, ice extent began to decline more quickly towards the end of the month.

Central Russia saw an early retreat of snow cover, as a result of prevailing warm conditions during the past winter over the eastern Arctic and Siberia.

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Ice extent declined through the month more slowly than usual, at an average rate of 29,950 square kilometers per day (11,560 square miles per day). The average daily rate of decline for 1979 to 2000 was 40,430 square kilometers (15,610 square miles) per day.

Cool conditions helped retain ice in Baffin Bay, between Canada and Greenland. Most of the ice loss during April was in the Kara Sea, north of Siberia, and the northern Baltic Sea in Europe. Ice also retreated rapidly in the western Bering Sea and the Sea of Okhotsk.

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For most of April, nearly all of the eastern Arctic, north of Europe and Russia, remained warmer than average. The largest anomalies were over central Russia, northern Siberia and the Laptev and East Siberian Seas, where temperatures averaged over the month were approximately 6 degrees Celsius (11 degrees Fahrenheit) above average. In contrast, most of the western Arctic was cooler than normal, with temperatures 6 degrees Celsius (11 degrees Fahrenheit) cooler than average over Davis Strait and Baffin Bay.

The eastern Arctic remained warmer than average all winter. This suggests that that sea ice there did not thicken as much as in past winters, and may retreat rapidly as the summer melt season progresses.

Read the whole report HERE.

SIE 2011 update 5: goodbye, April

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.

May 1st 2011

Another month has passed in the Arctic, a month in which extent decline saw a few of the usual hiccups, but overall remained quite steady. In the last week or so we have seen a very positive Arctic Oscillation move back to negative territory, resulting in a steep decline in trends. Whether this acceleration will be sustained in the coming month, remains to be seen. But I think it's safe to say that the melting season has now started in earnest.

As always we start the SIE update with IJIS SIE graph and we can clearly see how the 2011 trend line has made a smooth curve remaining in the middle of the pack and veering off slightly to the lower end:

The current difference between 2011 and the other years is as follows:

• 2005: -45(-26,297)
• 2006: +261K (-26,932)
• 2007: +76K (-27,521)
• 2008: -206K (-40,240)
• 2009: -453K (-26,781)
• 2010: -474K (-40,786)

Between brackets is the average daily extent rate for the month of April. 2011's average daily extent rate for April was -34,797 square km per day, which is less than the big 40K per day in 2008 and 2010, but way above the other years. 2011 has crept back and is very close to second position now, keeping 2009 and 2010 at a very safe distance. In the coming month leader 2006 will start to level off a bit, and 2010 starts its impressive decline.

As noted in the previous update the Cryosphere Today SIA anomaly graph showed an uptick that ended the flatlining around the minus 1 million square km mark. The anomaly number was almost halved to minus 500K km2 but then shot down again and is currently back to minus 1 million square km: