NASA - National Aeronautics and Space Administration

A Media Briefing on the State of Arctic Sea Ice

WASHINGTON -- The latest Arctic sea ice data from NASA and the National Snow and Ice Data Center show that the decade-long trend of shrinking sea ice cover is continuing. New evidence from satellite observations also shows that the ice cap is thinning as well. Scientists who track Arctic sea ice cover from space announced that this winter had the fifth-lowest maximum ice extent on record. The six lowest maximum events since satellite monitoring began in 1979 have all occurred in the past six years (2004-2009).

NASA and the National Snow and Ice Data Center in Boulder, Colo., will hold a media briefing on Monday, April 6, at 11 a.m. ET, to present the latest observations of sea ice conditions in the Arctic. Briefing visuals are listed below. For the complete story, click here.

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Background Information on Teleconference Speakers

> Walt Meier, research scientist, NSIDC
> Ron Kwok, senior research scientist, NASA JPL
> Tom Wagner, NASA cryosphere program manager

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Images and Multimedia in Support of the News Conference

Presenter: Walt Meier, research scientist, NSIDC

	Video: The solid blue line indicates daily sea ice extent from late 2008 to early 2009. The dashed green line indicates sea ice extent in winter 2006-07 (leading up to the record-low minimum in summer 2007). The solid gray line indicates average extent from 1979 to 2000. This year’s maximum winter ice extent occurred on February 28, 2009. Credit: National Snow and Ice Data Center > Larger image
	Figure 2: Maps show the relative age of Arctic sea ice at the end of February 2009 and over time. Thin, first-year ice is the predominant type covering the Arctic Ocean this winter. Credit: From NSIDC, courtesy Chuck Fowler and Jim Maslanik, University of Colorado > Larger image
	Figure 3: During the winter, winds and currents push some of the thick, multi-year ice out of the Arctic Ocean. In the past, that thicker ice was replenished by new ice that survived several summer melt seasons. Credit: From NSIDC, courtesy Chuck Fowler and Jim Maslanik, University of Colorado > Animated GIF

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Presenter: Ron Kwok, senior research scientist, NASA JPL

	Figure 1: ICESat measures the distances to the top of the snow cover and to the sea surface. The difference between the two quantities gives the total “freeboard” measurement; that is, the amount of ice above the water line relative to the local sea level. Credit: Courtesy of Norbert Untersteiner, University of Washington > Larger image
	Figure 2: This schematic shows the geometric relationship between freeboard (the amount of ice above the water line), snow depth, and ice thickness. Buoyancy causes a fraction (about 10 percent) of sea ice to stick out above the sea surface. By knowing the density of the ice and applying “Archimedes’ Principle” -- an object immersed in a fluid is buoyed up by a force equal to the weight of the fluid displaced by the object -- the total thickness of the ice can be calculated. Credit: Ron Kwok, NASA/JPL > Larger image
	Figure 3: Maps show the distribution of sea ice thickness over the Arctic Ocean during fall 2005 and winter 2006. The thickest ice is typically found north of Greenland and Ellesmere Island. The thickness (greater than 5 meters) is due to ice piling up against the coast. Credit: Ron Kwok, NASA/JPL > Larger image
	Figure 4: The decline in multiyear (including second-year ice) sea ice coverage has also been measured by NASA’s QuikScat satellite from 1999 to 2009. Each field shows the coverage on January 1 of that year. There is a 40 percent drop in coverage between 2005 and 2007. Credit: Ron Kwok, NASA/JPL > Larger image
	Figure 5: Maps compare ice thickness as measured by ICESat between the fall 2005 to winter 2006 and fall 2006 to winter 2007. Credit: Ron Kwok, NASA/JPL > Larger image

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Presenter: Tom Wagner, NASA Cryosphere Program Scientist, NASA's Goddard Spaceflight Center

Video: In commemoration of the end of the International Polar Year, Tom Wagner, NASA Cryosphere Program Scientist, appeared on television stations around the country on April 6, 2009. This video highlights his answers to questions about the IPY, climate change, and new data on the extent and thickness of sea ice covering the Arctic Ocean. Credit: NASA's Goddard Spaceflight Center > Watch the video

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Supplemental Imagery

	This data visualization from the AMSR-E instrument on the Aqua satellite show the maximum sea ice extent for 2008-09, which occurred on Feb. 28, 2009. Credit: NASA Goddard's Scientific Visualization Studio > Larger image
	Data visualization of Arctic sea ice thickness, as measured by ICESat, shows the decline of the thickest ice (white, 4 to 5 meters thick) and increase in thinner ice (deep blue, 0 to 1 meter) from 2003 to 2008. Credit: NASA Goddard's Scientific Visualization Studio > View Quicktime video > View color bar
	Data visualization of ice thickness, as measured by ICESat, shows the yearly growth (winter) and retreat (fall) of ice in the Arctic Ocean. Credit: NASA Goddard's Scientific Visualization Studio > View Quicktime video > View color bar

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The above data visualizations show a time series of Arctic sea ice thickness made by ICESat from 2003 to 2008. White patches are 4 to 5 meters thick; deep blue patches are 0 to 1 meter. Credit: NASA Goddard's Scientific Visualization Studio 2003 | 2004 | 2005 | 2006 | 2007 | 2008 > View color bar

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Related Links

> Satellites Show Arctic Literally on Thin Ice (Feature Story)
> Arctic Sea Ice Reaches Lowest Coverage For 2008
> NSIDC Arctic Sea Ice News and Analysis
> NASA and the International Polar Year
> ICESat