NOAA Earth System Research Laboratory
and NCAR Societal Impacts Program Seminar Series

Sheldon Drobot
Diagnosing the Recent Decline in Artic Sea Ice and Prospects for the Future

NCAR Societal Impacts Program (SIP)and Weather and Society Integrated Studies (WAS*IS)
David Skaggs Research Center (DSRC -NOAA Building)
325 BroadwayBoulder, Colorado 80305-3328
Room GC402 (Multipurpose Room)

Monday, July 28, 2008
2:00-3:00pm discussion following / refreshments will be served

Mention the WAS*IS Seminarwhen checking in throughDSRC security.
Questions/Problems Contact Julie Singewald
303-497-6818 Julie.Singewald@noaa.gov

Abstract: The decline in Arctic sea-ice is one of the more compelling and obvious signs of climate change. The total Arctic sea-ice extent has decreased by about 4% per decade from 1979–2007, with a larger decline of roughly 10% per decade from 1996–2007. The accelerating decline in Arctic sea-ice is driven by several record or near-record minima in sea-ice extent in the past few years, culminating in the exceptionally low 2007 sea-ice minimum cover of 4.13 million km2, which was 22% below the previous record set in 2005, and half as much as sea-ice minima from the 1950s through 1970s.

The rapid loss in sea ice raises numerous physical and societal questions, some of which include:

-Why is the ice decreasing?
-How well can we predict future ice conditions?
-What impacts will the loss of ice have on humans and the environment?

Drawing on my recent studies, as well as studies from the largerArctic research community, this presentation will explore these questions. Our current understanding suggests that the decline in Arctic sea-ice is related to a complex and possibly changing mixture of dynamic and thermodynamicforcings. This knowledge can be used to provide seasonal forecasts of Arctic sea-ice conditions, but decadal-scale forecasts are underestimating the recent ice loss. With respect to impacts of continued ice loss, the majority appear to be negative (e.g., loss of polar bear habitat), but there are some potential positives (e.g., navigable Northwest Passage). There also remain several unknowns, such as how weather patterns over the central USA may change.