1. ARCTIC SEA ICE COVER September 2005 NASA

2. SEA ICE EXTENT March 2006 Maximum September 2006 Minimum NEW RECORD! 2006: At or near record minimum in summer and winter

3. SEA ICE EXTENT Max. Extent: 2.5% per decade Min. Extent: 8.9% per decade 1979-2006: Decreasing trend

4. UCAR, Holland et al., 2006 The Road Ahead? Ice-free summers in foreseeable future

5. SEA ICE COVER aka ‘The Great Integrator’ Ocean heat flux Solar radiation THERMODYNAMICS Ice grow, melt and decay Ocean stress Wind stress DYNAMICS Ice motion Reflects impact of atmospheric and oceanic forcing

6. Arctic Oscillation (AO) Two Dominant Regimes Colder winter temperatures Strong Beaufort Gyre Warmer winter temperatures Transpolar Drift Stream sweeps ice out of Arctic Ocean Negative AOPositive AO ICE GAINS ICE LOSES

7. A tmospheric Oscillation (AO) Strong positive pattern dominated from 1989 – 1996 Favors loss of sea ice More neutral pattern from 2000 - 2006 Opportunity for recovery

8. Arctic Surface Air Temperature 1900- 2006 Arctic-wide, annual averaged SAT anomalies (60 – 90°N) over land 1980-present: Warming trend

9. Warming: Arctic trend consistent with global trend

10. March-May temperature anomaly composites Relative to a 1968-1996 base period SURFACE TEMPERATURE Despite shift, positive (warm) anomalies remain over the entire Arctic

11. Southeastern Bering Sea continental shelf mooring OCEAN Temperature 2006: Significant cooling compared to previous 6-years

12. Anomalies relative to EWG climatology (1950-1980s) NPEO surveys & J-CAD Morison et al., 2006a OCEAN North Pole Region 2000-2005: Relaxation to near pre-1990 climatology 2000 2005 SalinityTemperature Temperature & Salinity

13. 2006 Arctic Report Card Sea Ice Cover Arctic Oscillation Surface Temperature Ocean Temperature Why continued decrease in extent?

14. Absorbed sunlight Lower albedo Melting Absorbed sunlight Melting Lower albedo Absorbed sunlight Melting Lower albedo + ++ Positive Feedback Cycle

15. Rigor and Wallace, 2004 Sep 2006 Canada AlaskaAlaska Russia Older, thicker ice Sep 1987 Younger, thinner ice SEA ICE AGE (Think thickness) 1988-1990: Precipitous decrease in thick ice OW01234568 10+ Years Age:

16. PERENNIAL SEA ICE Older, thicker ice Rigor & Nghiem Significant decrease in older ice Strong & Persistent Positive AO

17. Sea ice cover susceptible to loss Strong & Persistent Positive AO (Less sea ice) + Rising Global Temperature Absorbed sunlight Lower albedo Melting + ++ Strong Positive Feedback Cycle + Confluence of Events…

18. State of the Arctic Sea Ice Cover Summary System under stress Destabilization? Arctic Oscillations Index  Through mid - 1990s: AO index effective predictor of trends in sea ice characteristics  1989-1996: Strong positive AO  2000s: AO shifted back to more neutral state Sea ice not following suit –Continued reduction in sea ice extent –Continued reduction in amount of older, thicker ice Will system rebound? or Has a ‘tipping’ point been reached?

19. International Polar Year http://www.ipy.org/

20. IMPACT OF IPY 2007-2008 June 2006 34 Platforms Reporting May 2007 >150 Platforms Reporting