West Antarctic Ice Sheet warming at twice the earlier estimate
US: A new analysis of temperature records by US researchers
suggests that the West Antarctic Ice Sheet (WAIS) is warming at twice
the rate previously thought.
According to the report published in the journal Nature Geoscience,
the study is based on data kept at Byrd station, established by the US
in the mid-1950s and located in the center of the WAIS.
Using a computer model of the atmosphere and a numerical analysis
method to fill in the missing observations, researchers found that the
average annual temperature increased 2.4C between 1958 and 2010.
“What we're seeing is one of the strongest warming signals on Earth,”
said Andrew Monaghan, co-author and scientist at the US National Centre
for Atmospheric Research.
“This is the first time we've been able to determine that there's
warming going on during the summer season.” he added. Researchers said
they found the first evidence of warming during the southern
hemisphere's summer months.
Although it is natural to expect warmer weather during Antarctic
summers, the region is so cold that makes it extremely rare for
temperatures to get above freezing.
Study co-author Prof. David Bromwich of Ohio State University,
therefore referred to the situation as a critical threshold.
“The fact that temperatures are rising in the summer means there's a
prospect of WAIS not only being melted from the bottom as we know it is
today, but in future it looks probable that it will be melting from the
top as well,” he said.
Scientists say that the rise in temperatures is caused by changes in
winds and weather patterns coming from the Pacific Ocean, but believe
further study would be needed to explore the role of human activities as
well. “We're seeing a more dynamic impact that's due to climate change
that's occurring elsewhere on the globe translating down and increasing
the heat transportation to the WAIS.” said Dr. Monaghan.
“This place has very variable weather - some of it is influenced by
human acts and some of it isn't. I think its premature to answer that
question right now.”
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