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Arctic
sea ice may be thinning faster than predicted because salty snow on the surface
of the ice skews the accuracy of satellite measurements, a new study from the
University of Calgary said on Tuesday.
The
report from the Canadian university's Cryosphere Climate Research Group
published in the academic journal Geophysical Research Letters found satellite
estimates for the thickness of seasonal sea ice have been overestimated by up
to 25 percent.
That
means the Arctic Ocean could be ice-free much sooner than some scientific
predictions, which forecast sea ice will first disappear completely during
summer months between 2040 and 2050, according to lead author Vishnu Nandan.
Ice-free
summers in the Arctic Ocean would impact global weather patterns by increasing
the magnitude and frequency of major storms, and alter the Arctic marine
ecosystem, making it harder for animals like polar bears to hunt.
There
are a wide range of projections as to when Arctic sea ice will start
disappearing in summertime as a result of warming global temperatures, and the
University of Calgary study calls into question satellite measurements provided
so far.
"The
problem is, microwave measurements from satellites don't penetrate the salty
snow very well, so the satellite is not measuring the proper sea ice freeboard
and the satellite readings overestimate the thickness of the ice," Nandan
said.
The
sea ice freeboard refers to ice that can be seen above sea level and
co-researcher John Yackel said, "Our results suggest that snow salinity
should be considered in all future estimates on the Arctic seasonal ice
freeboard made from satellites."
Reporting
by Nia Williams; editing by Diane Craft.
