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Remote Sensing of Sea Ice. Identification of Paleo -moraines Remote Sensing of Sea Ice Course Evaluations Final Exam on Friday, May 9, 3:00 – 5:30 PM Final Review Sheet and Possible Essay Questions Posted. Identification of Paleo moraines . Sea Ice.
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Remote Sensing of Sea Ice • Identification of Paleo-moraines • Remote Sensing of Sea Ice • Course Evaluations • Final Exam on Friday, May 9, 3:00 – 5:30 PM • Final Review Sheet and Possible Essay Questions Posted
Sea Ice • Why do we care about sea ice trends? • Why is sea ice important from a climate science perspective?
Sea Ice Extent Annual Anomalies Major reductions in sea ice extent in NH! Slight increases in SH
September 1999 March 2000
September 2011 March 2012
Arctic Sea Ice Extent from Satellite Data Median ice edge NASA and NSIDC
Arctic Sea Ice Extent from Satellite Data NASA and NSIDC
Melting of sea ice dramatically changes the energy balance in the Arctic Ocean Sun solar radiation 45 – 95% reflected sea ice 85 – 95% absorbed ocean Credit: C.L. Parkinson / NASA / GSFC
Perennial or Multi-Year Sea Ice • Perennial sea ice has been decreasing at a greater rate than has total sea ice in the Arctic • More first-year sea ice means that it’s easier to melt each year because it’s thinner
Near-Minimum Sea Ice Extent -- 2012 SVS GSFC/ NASA
Minimum Multi-Year Sea Ice Extent -- 2012 Multi-Year Sea Ice Russia Greenland Alaska Canada J.C. Comiso / NASA
Sea Ice Videos • http://www.youtube.com/watch?v=Co68_tod0dQ • http://www.youtube.com/watch?v=6j8SGs_gnFk
Recent Sea Ice Trends • Recent years have seen the downward trends in sea ice extent continue for the Arctic. • Higher summer temperatures, changing wind/ocean currents • Less multi-year (i.e., thick!) ice remaining • Slight increases in sea ice extent are evident in the Antarctic. • More precipitation (snow and rain = decreased salinity of ocean water which raises its freezing point?) • More snow during autumn freeze up which allows ice to form more quickly?
Sea Ice Links • http://ice-glaces.ec.gc.ca/App/WsvPageDsp.cfm?Lang=eng&lnid=27&ScndLvl=no&ID=238 • http://nsidc.org/seaice/study/remote_sensing.html