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Climate Change in Earth’s Polar Regions

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Presentation on theme: "Climate Change in Earth’s Polar Regions"— Presentation transcript:

1 Climate Change in Earth’s Polar Regions
Ben Holt Oceans-Ice Group Jet Propulsion Laboratory Arctic Ocean, 1982

2 Global Temperature Change Enhanced at Poles
transport of air poleward by atmospheric circulation Average Surface Temperature Change, Relative to the Average (◦C)

3 Sunlight Reflectivity on Ice and Ocean
100 % Reflected 85% Sunlight 100 % Reflected 7% Water Absorbs 93% Ice / Snow Absorbs 15% •Increased warming => less ice => more open water => warmer water =>more ice melt and so on

4 Arctic and Antarctic Ice as key indicator of climate change
Barrow, Alaska +30°F South Pole -80°F !! current state seasonal cycle of growth and melt, with opposite seasons / Sea Ice (colored) and Land Ice (white)

5 Arctic Sea Ice – Reduced Extent
September 19, 2010 Satellite Record recent accelerated increase is faster than climate model projections May lead to nearly ice-free summer Arctic. Slight upward trend in Antarctic sea ice 11.5 % Reduction Per Decade since 1979

6 Arctic Sea Ice Thickness Submarine and Satellite Record 1958-2007
Submarine operations related to cold war activities •Sea ice thickness shows decadal thinning – over 40 % Reference: Kwok & Rothrock, Geophysical Research Letters, 2009

7 Glaciers, Greenland, Antarctica ~Water stored above sea level
Land Ice Glaciers, Greenland, Antarctica Very thick and old balance of accumulation at higher elevations and loss at edges ~Water stored above sea level

8 Greenland Ice Mass Loss 2002-2009
Derived From NASA GRACE Gravity Mission Greenland Change in Ice Mass Loss Gigatons greatest decrease at margins to south Velicogna, Geophysical Research Letters, 2009 •Contributes to sea level rise J. Wahr, U. Colorado

9 2009 NOAA Arctic Report Card
“Warming of the Arctic continues to be widespread, and in some cases, dramatic. Linkages between air, land, sea, and biology are evident.” Sea ice loss impacts habitat of large marine mammals Will this lead to nearly ice-free arctic? Increased interest in human-related activities including shipping and oil exploration

10 Backup

11 Evidence and Impact of Arctic Warming
•Sea ice – thinning (>40%) and shrinking (11.5% / decade) •Permafrost melting – also releases methane •Land ice melting – sea level change •Loss of sea ice – impacts habitat of polar bears, walruses •Ecosystem shifts – from Arctic to subarctic communities •Increase human activities – shipping and oil production

12 Sources, References

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