September Sea Ice Outlook: August Report

Release Date: 
15 August 2011

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Many thanks to all contributors to the August Sea Ice Outlook. We received 21 responses for the Pan-Arctic report (Figure 1), with estimates in the range of just below 4.0 million square kilometers to as high as 5.4 million square kilometers for the September arctic mean sea ice extent. As in the July Outlook, the median value was 4.6 million square kilometers with quartile values of 4.3 and 4.6 million square kilometers, a rather narrow range. All contributions are well below the 1979-2007 climatological mean of 6.7 million square kilometers, and also below all values seen prior to 2007. Thus, the low values observed the last four summers are expected to continue again this September. On a regional level, the long-term downward trend is expected to continue in all regions except the Greenland Sea.

July 2011 set a new record low for the month during the satellite data record despite a significant slowing down of ice loss during the latter half of the month as weather changed to cooler conditions. In August, warmer conditions returned, which combined with a rather diffuse ice cover in the Beaufort and Chukchi seas, has led to a speed-up in the rate of ice loss at the beginning of August, particularly in the Chukchi Sea. Whether or not this rate of ice loss will continue will depend on what the weather does over the next few weeks. However, with approximately a month left in the melt season, it is very unlikely that the September minimum will end up above 5 million square kilometers.

Credit: Arctic Research Consortium of the U.S. (ARCUS).Figure 1. Distribution of individual Pan-Arctic Outlook (August Report) values for September 2010 sea ice extent. Credit: Arctic Research Consortium of the U.S. (ARCUS). Click to enlarge.

Download High Resolution Version of Figure 1.