Melting Arctic Sea Ice to Pause and Possibly Expand in Coming Decades
12.08.2011 - Water & Oceans, Ice & Snow, Arctic
New research recently published in the Geophysical Research Letters suggests that even as Arctic sea ice extent is predicted to continue to decline as the planet warms over the long term, it could temporarily stabilize and even slightly expand in the coming decades. A team of researchers of the National Center for Atmospheric Research (NCAR) made the surprising discovery while conducting a series of computer simulations.
The resarch team was interested in understanding why Arctic sea ice shrank more rapidly in the late 20th century than computer models predicted. Since the advent of satellite measurements in 1979, summer sea ice cover in the Arctic has shrunk by one third.
The new series of simulations the research team ran indicate that the extent of sea ice is not only be determined by anthropogenic forcing; it also largely depends on climate variability, which is unpredictable, according to lead author Jennifer Kay. The study's co-author, Dr. Marika Holland, said that both positive and negative trends are likely to "become more pronounced in a warming world," with year-to-year and decade-to-decade trends in the extent of sea ice are likely to fluctuate increasingly as temperatures warm and the ice thins. This means that natural variation trends will be come more pronounced as the planet warms, with periods of sea ice growth and periods of sea ice decline likely to be more extreme than before.
However the authors of the study caution that additional modelling studies and longer-term observations will be needed to better understand the impacts of climate change and weather variability on Arctic sea ice.