September-October 2011

Third IceBridge campaign in Antarctica

Researchers with NASA's Operation IceBridge campaign began in October the mission's third year of aerial surveys of Antarctica. The team uses several remote-sensing instruments loaded into two planes, a DC-8 jet and a Gulfstream V jet. The planes fly to Antarctica from a base in Punta Arenas, Chile, and cover not only new routes, but also previous flight lines to measure how much glaciers and ice sheets have changed since the last time they were surveyed.
On Oct. 14, IceBridge scientists observed a massive crack running across the ice shelf of Pine Island Glacier in West Antarctica. The rift indicated that the glacier, which is rapidly melting and contributing to sea level rise, is about to shed a 300-square-mile iceberg to the ocean.    
> Visit Operation IceBridge’s website for more information on the mission.

Arctic sea ice at its second minimum

Satellite data from NASA and the National Snow and Ice Data Center showed that the sea ice cover of the Arctic Ocean was at its second-lowest extent on record this September. Cryospheric lab’s Joey Comiso said that the pace of the decline is also accelerating, with the older, thicker ice declining faster than the rest. Comiso’s analysis of Arctic sea ice using data from the microwave radiometer on the Aqua satellite showed that while the sea ice extent was larger than during the 2007 minimum record, the sea ice area was slightly lower than 2007 levels for about 10 days in September. Sea ice area equals the actual surface area covered by ice, while extent includes any zone where ice covers at least 15 percent of the ocean.

> Read NASA’s press release on Arctic sea ice extent minimum in 2011.

Snow cover map

Dorothy Hall and colleagues recently launched an interactive, near-real-time map of snow cover in North America. The map visualizes data from the Moderate-resolution Imaging Spectroradiometer (MODIS) instruments on the Terra and Aqua satellites and it’s updated daily. Users can zoom in on their geographical areas of interest and download images at different resolutions. Although MODIS can’t see snow cover beneath clouds, the website allows users to use filters to grey out the cloud cover or highlight the snow cover layers, to better visualize what areas are covered in snow.
> Check the Daily North American Snow Cover map.