Arctic Sea Ice in 2008: Standing on the Threshold Mark Serreze, Walt Meier, Julienne Stroeve, Ted Scambos, Stephanie Renfrow National Snow and Ice Data Center (NSIDC) Cooperative Institute for Research in Environmental Sciences at the University of Colorado at Boulder
September 2007: A New Record Minimum Stroeve et al. 2008
Observed Rate of Ice Loss Exceeds Expectations Updated from Stroeve et al., 2007
Standing on the Threshold? Has the sea ice cover been preconditioned to such a degree through thinning that a strong “kick” from natural variability can initiate a rapid slide towards ice-free conditions in summer? Has the kick already occurred? Was the kick the “perfect storm” associated with the record 2007 minimum? All eyes were on 2008.
Even More Young, Thin Ice than in Spring 2007 NIC Analysis of Multiyear Ice Fraction Estimated Ice Age from Tracking Algorithm National Ice Center (left), J. Maslanik (right)
Ice Extent through June 3: On Track http://nsidc.com/arcticseaicenews/
July: Falling Off the Pace By early July, it was clear that we had fallen “off the pace” of 2007. Atmospheric circulation patterns were not as favorable as in 2007. Setting a new record minimum started to seem less likely.
No “Perfect Storm” as Seen in 2007 SLP, July 2008 SLP, July 2007 NSIDC and NOAA Climate Diagnostics Center
August: Stirring the Pot By early August, the rate of ice loss usually starts to slow – this was seen even in 2007. In 2008, ice extent continued downward at a brisk pace. A change in atmospheric circulation “stirred the pot.” We started to run out of ice thickness.
The Plot Thickens August 26: Ice extent falls to second lowest in satellite record http://nsidc.com/arcticseaicenews/ (left), University of Bremen (right)
Amundsen’s NW Passage opens And Thickens Amundsen’s NW Passage opens Remarkable ice losses in Chukchi and East Siberian seas J. Stroeve, W. Meier (NSIDC) and University of Bremen
2008 Falls Just Short Sept 14, 2008: 4.51 million sq. km Left: From Serreze et al. (2008); Right: Updated from Stroeve et al. (2007) 12
Parting Thoughts Was 2007 the kick? We’ll see. NSIDC will be giving the blow-by-blow account of 2009. http://nsidc.com/arcticseaicenews/ Ice-free summers by 2030? Perhaps even earlier? We need to be ready
Thank You 14