Arctic sea ice, a key indicator of climate change, could be dwindling faster than predicted, according to a study by the University of Calgary, Canada.
Research undertaken by the Cryosphere Climate Research Group under the Department of Geography at the university has found that satellite measurements over the years have overestimated the thickness of Arctic sea ice by as much as 25% because of the presence of salty snow.
“The implication is that the prediction of an ice-free Arctic ocean in summertime by 2050 could happen much earlier,” says Vishnu Nandan, lead author of the work published in Geophysical Research Letters, a peer-reviewed journal by the American Geophysical Union. Dwindling ice cover hastens the warming of oceans, and has an impact on weather phenomena like the El Nino that influences the Asian monsoon.
“The thinning ice would make it difficult for animals like polar bears and seals and organisms like phytoplankton to survive,” says Mr. Nandan who hails from Thiruvananthapuram.
The study, based on satellite data and extensive field measurements, found that salty snow — formed when brine is expelled upward from the ice surface — does not allow radar waves from satellites to penetrate, leading to skewed measurements.
Correction factor
The researchers have proposed a snow salinity correction factor that could bring down the error in estimation of sea ice thickness.
Mr.Nandan and his team members braved the hostile weather, polar bears and treacherous ground in the Canadian Arctic to generate field data for the study.
“We spent months in sub-zero temperatures to minus 40 degrees. The barren land, deafening silence and absence of communication often got on our nerves. Our only contacts were with the Inuit people who guided us through the ice routes”, recalls Mr. Nandan who has worked on Antarctic ice shelves during a previous stint at the Alfred Wegener Institute, Germany.
Research undertaken by the Cryosphere Climate Research Group under the Department of Geography at the university has found that satellite measurements over the years have overestimated the thickness of Arctic sea ice by as much as 25% because of the presence of salty snow.
“The implication is that the prediction of an ice-free Arctic ocean in summertime by 2050 could happen much earlier,” says Vishnu Nandan, lead author of the work published in Geophysical Research Letters, a peer-reviewed journal by the American Geophysical Union. Dwindling ice cover hastens the warming of oceans, and has an impact on weather phenomena like the El Nino that influences the Asian monsoon.
“The thinning ice would make it difficult for animals like polar bears and seals and organisms like phytoplankton to survive,” says Mr. Nandan who hails from Thiruvananthapuram.
The study, based on satellite data and extensive field measurements, found that salty snow — formed when brine is expelled upward from the ice surface — does not allow radar waves from satellites to penetrate, leading to skewed measurements.
Correction factor
The researchers have proposed a snow salinity correction factor that could bring down the error in estimation of sea ice thickness.
Mr.Nandan and his team members braved the hostile weather, polar bears and treacherous ground in the Canadian Arctic to generate field data for the study.
“We spent months in sub-zero temperatures to minus 40 degrees. The barren land, deafening silence and absence of communication often got on our nerves. Our only contacts were with the Inuit people who guided us through the ice routes”, recalls Mr. Nandan who has worked on Antarctic ice shelves during a previous stint at the Alfred Wegener Institute, Germany.