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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.
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3/20/2001Arctic Sea Ice ClassesPerennial ice
Seasonal ice
Mixed ice
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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
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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.
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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
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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.
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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
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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.