Observing the State of Arctic Sea IceS. V. Nghiem1, I. G. Rigor2, P. Clemente-Colón3, D. K. Perovich4, H. Eicken5, J. E. Overland6, T. Markus7, D. G. Barber8, and G. Neumann1

1Jet Propulsion Laboratory, California Institute of Technology, CA2Applied Physics Laboratory, University of Washington, WA

3U.S. Naval and National Ice Center, MD4Cold Region Research and Engineering Laboratory, NH

5Geophysical Institute, University of Alaska, AK7NASA Goddard Space Flight Center, MD8CEOS, University of Manitoba, Canada

State of the Arctic ConferenceMiami, Florida, March 2010

Copyright 2010. All rights reserved.

2Nghiem/

3/20/2001Arctic Sea Ice ClassesPerennial ice

Seasonal ice

Mixed ice

3Nghiem/

March 1970-1999:Decrease of 0.5x106km2/decade.

1957-1999

`

Estimate for 2008:3.8 million km2

Stationary ProcessFX(t) = FX(t+∆t)Long-term behavior is usable in forecast

4Nghiem/

2008

March 2000-2008:Decrease of 1.5x106km2/decade.

Measure in 2008:1.7 million km2

Non-StationaryFX(t) = FX(t, t+∆t)The “Old Wisdom” is not applicable.

5Nghiem/

Ice compression from East to West Arctic Ice compression into Transpolar Drift (TD)Acceleration of TD1carrying ice out of Arctic via Fram StraitWarm Atlantic water effectively melted ice in Greenland Sea

‘The Polar Express’Nghiem et al. GRL, 2007

1Gascard et al., EOS, 2008: Acceleration of the TD

6Nghiem/

The Polar Express in 2007

SEA ICECLASSES

Mixed ice

Perennial

Melt

Seasonal

Animationof sea ice20 framesper second

Products for Observing State of Arctic Sea Ice

• Sea ice melt detection by active and passive microwave sensors.

• Experimental melt product in Seasonal Ice Zone Observing Network (SIZONet).

• Composite sea ice product from scatterometer and synthetic aperture radar data.

9Nghiem/

Sea Ice Melt Detection and Albedo TransitionComparison with C-ICE observations in the Parry Channel

AMSR-E QuikSCAT

Seasonal Ice Zone Observing NetworkExperimental Product for Melt Detection

Scale 1:29,000,000

12Nghiem/

SAR signatures of various ice classes for sea ice classificationReferences:Nghiem and Bertoia, CJRS, 2004.Nghiem, JPL D-40340, 70 pp., March 2007.

Summary• Non-stationary process of decrease in the extent of perennial sea ice.

• Loss rate tripled in decade of 2000s compared to that in 1970s-1990s.

• The Polar Express: Dynamic effects are important in contributing to perennial sea ice loss.

• The extent of perennial ice extent remained low in 2009.

• More products of observing state of Arctic sea ice: Melt, SIZONet, composite QS/GMM.