Sea Ice Outlook: August Report

Release Date: 
19 August 2009

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The outlook for arctic sea ice in September 2009, based on July data, indicates a continuation of low pan-arctic sea ice extent and no indication that a return to historical levels will occur.

The August Sea Ice Outlook Report is based on a synthesis of 13 pan-arctic contributions (plus nine updates from participating regional groups) utilizing a range of methods.

Figure 1.Figure 1. Distribution of individual outlook values for September 2009 sea ice extent based on July data.

The range of individual outlook values this month is from 4.2 to 5.0 million square kilometers, with more than half of the estimates in a narrow range of 4.4 to 4.6 million square kilometers, representing a near-record minimum. All estimates are well below the 1979–2007 September climatological mean value of 6.7 million square kilometers. The uncertainty / error values, from those groups that provided them, are about 0.4 million square kilometers, thus most of the estimates overlap.

Warm, clear conditions led to significant sea ice melt during the month of July, with some areas of unusually low ice extent and an atmospheric pattern that promotes summer sea ice loss in the Pacific sector of the Arctic. At this point in the sea ice season, the minimum extent will largely be driven by atmospheric conditions, including winds and temperatures.

This August report will be the last formal monthly Sea Ice Outlook this season, though we will provide a short announcement when the sea ice minimum is reached in September. To track the approach to this year's minimum, visit the NSDIC Arctic Sea Ice News and Analysis website, which has daily updates of arctic sea ice.