Cool Geo-Pic: Amount of Old Ice in Arctic Hits Record Low in February 2009

This Cool Geo-Pic comes again from NASA's Earth Observatory. While the loss of perennial sea ice opens trade routes, its seems a pale trade-off given the global impact of climate change, sea level rise and the more imaginative tales of polar shift.

Quick "Cut & Paste" Highlights:

" ...The summer minimum and the winter maximum are the two pivotal milestones in the annual cycle of Arctic sea ice. The thickness of sea ice and the extent at each of these times are key indicators of Arctic climate. Over the past two and a half decades, the extent of sea ice at the end of summer (mid-September) has declined significantly. The corollary to that trend is that at the winter maximum (end of February or mid-March), the ice covering the Arctic is much younger and thinner than it was in the past...."

"...The age of ice in the winter pack is important because young ice is thin and likely to melt in the upcoming summer. Historically, a large “core” of sea ice survived the summer. Around the margins of the perennial ice, new ice forms each winter and melts each summer. Ice that survives the summer melt thickens and hardens through freezing of new water and collisions with other ice floes, which builds thick ridges of ice....."

Full Article - Click Here

References / Credits:

Maslanik, J., Fowler, C., Stroeve, J., Drobot, S., Zwally, J., Yi, D., and Emery, W. (2007). A younger, thinner Arctic ice cover: Increased potential for rapid, extensive sea-ice loss. Geophysical Research Letters, 34, L24501.
National Snow and Ice Data Center. Arctic Sea Ice News & Analysis. NSIDC Website. Accessed April 8, 2009.

Further Reading:
NASA satellites show Arctic literally on thin ice.
Dwindling Arctic Ice.
NASA images by Jesse Allen, based on data provided by James Maslanik and Chuck Fowler, University of Colorado and NSIDC. Caption by Rebecca Lindsey, with input provided by Walt Meier, NSIDC.
Instrument:
DMSP