- Category: Politics
15 Feb 2013
- Published on Friday, 15 February 2013 09:14
- Hits (1973)
The CryoSat-2, a satellite launched by the European Space Agency just two years ago, has confirmed that not only has Arctic sea ice been declining, it’s been losing in volume as well.
While other satellites have already shown drops in the area covered by Arctic sea ice, the CyroSat-2 is the first to measure the volume of sea ice, a much more accurate indicator of the changes taking place in the Arctic.
The CryoSat-2, which was launched in April of 2010 by the European Space Agency, is part of the CryoSat program to study the Earth’s polar ice caps.
Using data from CryoStat-2 spanning 2010 to 2012, and data from NASA’s ICESAT satellite from 2003 to 2008, researchers from the Centre for Polar Observation and Modeling at the University College of London estimated the volume of sea ice in the Arctic.
The team found that, from 2003 to 2008, autumn volumes of ice averaged 11,900 km3. From 2010 to 2012, the average autumn volume had dropped to 7,600 km3 – a decline of 4,300 km3.
In winter, average ice volumes were 16,300 km3 from 2003 to 2008 and 14,800 km3 between 2010 and 2012 – a difference of 1,500 km3.
“The data reveals that thick sea ice has disappeared from a region to the north of Greenland, the Canadian Archipelago, and to the northeast of Svalbard,” said Dr. Katharine Giles of U.C.L. Earth Sciences.
CryoSat-2 measures ice volume using a high-resolution synthetic aperture radar altimeter, which fires pulses of microwave energy down towards the ice. The energy bounces off both the top of sections of ice and the water in the cracks in between. The difference in height between these two surfaces lets scientists calculate the volume of the ice cover.
"While two years of CryoSat-2 data aren't indicative of a long-term change, the lower ice thickness and volume in February and March 2012, compared with same period in 2011, may have contributed to the record minimum ice extent during the 2012 autumn," said Professor Christian Haas of York University, Canada Research Chair for Arctic Sea Ice Geophysics and coordinator of the international CrySat sea ice validation activities.
The findings confirmed the continuing decline in Arctic sea-ice volume simulated by the Pan-Arctic Ice-Ocean Modeling and Assimilation System, which estimates the volume of Arctic sea ice using date from submarine, mooring, and satellite observations.
CryoSat-2’s estimates were also confirmed using measurements from three independent sources – aircraft, moorings and NASA’s Operation IceBridge.
The study is a huge international collaboration between U.C.L. and the E.S.A., along with the Jet Propulsion Laboratory, the University of Washington, York University, Alfred Wegener Institute for Polar and Marine Research, Woods Hole Oceanographic Institution, Morgan State University and the University of Maryland.
The research was funded by the Natural Environment Research Council, the European Space Agency, the German Aerospace Center, Alberta Ingenuity and the National Science Foundation. – K.R. Jalbuena