Arctic winter sea ice down 9% since 2003
Last updated on 15 February 2013, 9:11 am
Arctic sea ice levels dropped 36% in the autumn and 9% in the winter between 2003 and 2012 according to analysis from the American Geophysical Union (AGU).
Researchers used new data from the European Space Agency’s CryoSat-2 satellite spanning 2010 to 2012, and data from NASA’s ICESat satellite from 2003 to 2008 to estimate the volume of sea ice in the Arctic.
The news is the latest in a pattern of falling ice levels in the region.
“The important thing is the volume loss rather than the area loss,” ice expert Professor Peter Wadhams from Cambridge University told RTCC.
“This paper deals with volume, which is critically dependent on thickness. The CrysoSat satellite gives thickness; so does the submarine [data].
“Earlier publications on percentage decreases of Arctic sea ice in different seasons dealt only with area, which (initially) is a slower loss rate.”
The findings confirm the continuing decline in Arctic sea-ice volume simulated by the Pan-Arctic Ice-Ocean Modelling and Assimilation System (PIOMAS), which estimates the volume of Arctic sea ice and had been checked using earlier submarine, mooring, and satellite observations until 2008.
“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, co-author of the study.
Other satellites have already shown drops in the area covered by Arctic sea ice as the climate has warmed.
CryoSat-2, launched in April 2010, differs in that it lets scientists estimate the volume of sea ice – a much more accurate indicator of the changes taking place in the Arctic.