Global Ice Coverage Claire L. Parkinson NASA Goddard Space Flight Center Presentation to the Earth Ambassador program, meeting at NASA Goddard Space Flight Center, Greenbelt, Maryland, October 14, 2011

Ice: Sample Views (MODIS image from the Terra satellite) (Photo by C. Parkinson) (Photo by L. Thompson) Sea ice Antarctic Ice Sheet Iceberg Sea ice and icebergs from space Ice and snow in the Andes (Photo by M. Deneyer) (Composite image from Canada’s Radarsat) (MODIS image from the Aqua satellite) Greenland Ice Sheet

Animation of 2007 Arctic Sea Ice Coverage, from DMSP Special Sensor Microwave Imager (SSMI) Data Images every 2 days White: Highly compact ice. Shades of light blue: Ice of lesser compactness. (animation by N. DiGirolamo and C. Parkinson) DMSP = Defense Meteorological Satellite Program

Albedo Contrast: Ice versus Water (animation by NASA GSFC SVS, C. Parkinson, M. Starobin, S. DeWitt, available at ) (GSFC = Goddard Space Flight Center; SVS = Scientific Visualization Studio)

Monthly Arctic Sea Ice Extents November 1978 – December 2009 (extended from C. Parkinson, D. Cavalieri, P. Gloersen, J. Zwally, and J. Comiso, J. Geophysical Research, 1999) based on data from the Nimbus 7 Scanning Multichannel Microwave Radiometer (SMMR), DMSP SSMI, and Aqua Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E)

Monthly Arctic Sea Ice Deviations, 11/1978 – 12/2009, from satellite SMMR, SSMI, and AMSR-E data (updated from Parkinson et al. 1999)

Arctic Record Low Sea Ice Coverage, September 14, 2007 from Aqua AMSR-E data (from NASA GSFC SVS)

2011 Arctic Sea Ice Coverage, up to October 10, in comparison with earlier satellite data (Map and plot from J. Comiso, C. Parkinson, T. Markus, D. Cavalieri, and R. Gersten, updated weekly on the NASA GSFC Cryospheric Sciences website, at neptune.gsfc.nasa.gov/csb/index.php?section=234)

2011 Arctic Sea Ice Coverage, up to October 10, in comparison with (Map and plot from J. Comiso, C. Parkinson, T. Markus, D. Cavalieri, and R. Gersten, updated weekly on the NASA GSFC Cryospheric Sciences website, at neptune.gsfc.nasa.gov/csb/index.php?section=234)

Laser Altimetry from the Ice, Cloud, and Land Elevation Satellite (ICESat) (Schematic from the ICESat Science Team)

February-March Arctic Sea Ice Thickness from ICESat Data (Images from Kwok et al. 2009) MY ice = Multi-year ice FY ice = First-year ice

Sample Impact of Reduced Sea Ice Coverage on Polar Bears (one of numerous species impacted) Earlier ice breakup forces earlier polar bear retreat to land. Changes in Western Hudson Bay polar bears: –Population decrease from about 1,200 in 1989 to about 950 in –Adult female average weight, 295 kg in 1980, 230 kg in (Photo by Robert Taylor) Date of Western Hudson Bay ice breakup down to 50% (From I. Stirling and C. Parkinson, 2006)

Animation of 2007 Antarctic Sea Ice Coverage from DMSP SSMI Data Images every 2 days. White: Highly compact ice. Shades of light blue: Less compact ice. (animation by Nick DiGirolamo and Claire Parkinson)

Winter and Summer Southern Ocean Sea Ice Coverages Derived from Satellite Passive-Microwave Data The values mapped are sea ice concentrations (percent areal coverages of ice).

Monthly Antarctic Sea Ice Extents November 1978 – December 2009 (extended from J. Zwally, J. Comiso, C. Parkinson, D. Cavalieri, and P. Gloersen, J. Geophysical Research, 2002) from satellite SMMR, SSMI, and AMSR-E data

Monthly Antarctic Sea Ice Deviations, 11/1978 – 12/2009, from satellite SMMR, SSMI, and AMSR-E data (updated from Zwally et al. 2002)

2011 Antarctic Sea Ice Coverage up to October 10, in comparison with earlier satellite data (from J. Comiso, C. Parkinson, T. Markus, D. Cavalieri, and R. Gersten, updated weekly at neptune.gsfc.nasa.gov/csb/index.php?section=234)

Yearly Averaged Sea Ice Extents, , for Five Southern Ocean Regions and the Total Weddell Sea Indian Ocean Western Pacific Ocean Ross Sea Bellingshausen/Amundsen Seas (from C. Parkinson and D. Cavalieri)

The Earth’s Two Remaining Massive Ice Sheets Greenland, July 13, 2002 Antarctica, composite image from several dates as imaged by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite

(Schematic by C. Shuman, C. Parkinson, and D. Hall)

Formation of Iceberg B15 and Its Breaking Off from Antarctica’s Ross Ice Shelf, from the Terra MODIS 3/28/2000 3/3/2000

Recent Changes in the Greenland Ice Sheet (From J. Zwally and the ICESat Science Team) Elevation changes, , derived from ICESat data Changes in ice mass, , derived from GRACE data (From S. Luthcke and the GRACE Science Team) ICESat = Ice, Clouds, and Land Elevation SatelliteGRACE = Gravity Recovery and Climate Experiment

Recent Changes in the Antarctic Ice Sheet Trend in the equivalent depth of water (cm/yr) in the Antarctic ice sheet, July 2003 – July 2007, from GRACE satellite data (from S. Luthcke and the GRACE Science Team)

Global Sea Level Change, , from radar altimeters on TOPEX/Poseidon and Jason-1 (From G. Mitchum and R. Nerem, 2007) Spatial distribution of sea level change, Globally averaged sea surface height, TOPEX = Topography Experiment

Summary Most of the Earth’s ice is in the ice sheets of Greenland and Antarctica. Substantial additional ice exists in other glaciated land areas and in the sea ice covers of the Arctic and the Antarctic. Satellite passive-microwave data have revealed many details about the global sea ice cover, including large seasonal cycles, much interannual variability, and statistically significant overall trends in the ice covers since the late 1970s. –Overall, the Arctic sea ice has decreased substantially since the late 1970s. –The Antarctic sea ice has increased somewhat since the late 1970s. Satellite altimeters and gravity monitors have revealed changes in the Greenland and Antarctic ice sheets. Decreases in land ice coverage have contributed to sea level rise.