University of Georgia
Antarctica Climate
Antarctic Sea Ice: Archives of Climate
 
>>Elizabeth Benyshek: The Antarctic and Arctic are both cold and remote areas, but the dynamics of sea ice in these polar regions differ from one another because of their unique geographies. Sea ice is an integral component in Earth’s global climate system. It covers more than 25 million square kilometers of Earth’s surface - about two-and-a-half times the area of Canada.
 
Sea ice reflects sunlight, keeping temperatures in the polar regions cool. If gradual warming temperatures continue to melt sea ice over time, more solar energy will be absorbed, perpetuating this cycle. Sea ice is essential to the health of Antarctic ecosystems, yet little is known about how changing climatic conditions and sea ice dynamics will impact these communities.
 
>>Caren Remillard: Oceans surrounding Antarctica promote larger concentrations of sea ice. Sea ice extent peaks in September at the end of winter in the Southern Hemisphere.  It retreats to a minimum in February during summer. Seasonal changes result in a loss of an average of 15 million square kilometers in Antarctica. Sea ice changes vary around the Antarctic continent. A prime example of this is The Ross Sea, which has exhibited a positive trend in sea ice extent while the Bellingshausen and Amundsen Seas to the East have displayed a decrease.
 
>>Eduardo Rendon: Sea ice makes field surveying difficult and costly for scientists. NASA Earth Observing Systems make it possible to study sea ice characteristics in these locations year-round. 
 
Our project partners, research scientists from the Wadsworth Center and The University of Georgia, are interested in broadening their understanding of annual and multiannual sea ice dynamics at their field sites Explorers Cove, Bay of Sails, and Ferrar Glacier in western McMurdo Sound, Antarctica.
 
>>Sean Cameron: NASA’s Terra satellite views the Earth's surface every day, acquiring data in 36 groups of wavelengths. The MODIS sensor onboard Terra tracks a wide array of Earth’s system interactions between the atmosphere, ocean, land, snow, and ice. Data acquired from Terra promotes understanding of energy balance and climate regimes. Our team analyzed MODIS-derived sea and ice surface temperature data from 2003 to 2008 in conjunction with sea ice extent data to gain a better understanding of the seasonality in McMurdo Sound.
 
Our team also utilized NASA’s Ice, Cloud and land Elevation Satellite, known as ICESat. Using three laser sensors, ICESat acquired a large volume of data from 2003 to 2008. ICESat was especially valuable to us since its orbit inclination ensured a high concentration of observations at the polar latitudes. ICESat allowed us to examine sea ice topography and calculate changes in thickness.


>>Elizabeth Benyshek: The 5 year span of ICESat and Terra data our team analyzed was acquired from The National Snow and Ice Data Center and processed to extract surface temperature, extent, and thickness values. Using ArcGIS, we created time series maps for surface temperature and sea ice extent to compare yearly and seasonal changes. This allowed us to make observations about localized short-term trends in sea ice dynamics in our partners’ region of interest. 


We found that the western coast of McMurdo Sound displayed an increase in sea ice extent and a decrease in thickness, while relative sea surface temperature increased. Changes in these vital components of sea ice systems affect nutrient supply to benthic communities, directly affecting productivity and local communities studied by our project partners.