Airborne Thickness Survey of Arctic Ice Offers Reassuring Feedback
17.06.2010 - Water & Oceans, Ice & Snow, Arctic
A team of researchers from the University of Alberta dispatched an electromagnetic "bird" to the Arctic to provide a more detailed look of the actual state of the sea ice. The data they collected seems reassuring, as they found large expanses of ice four to five metres thick.
The study, published in Geophysical Research Letters, reports only minimal changes in the sea ice since 2007 and variations within the range of natural variability. Moreover, going into the melt season, the sea ice appears to be in much better shape than it has been in previous seasons.
As to how the ice will survive the melt season, the team believes that a lot will depend on the wind, but that the ice decline that has been underway for at least 30 years will continue. Part of the problem with ice forecasting, however, is that it is based largely on satellite data. While this data can determine the expanse of ice, it says close to nothing about its thickness, an essential criterion to determine how well Arctic sea ice will survive the summer.
By taking their instrumentation into the air, the team was able to cover a survey route close to 2,400 kilometres, adding a necessary third dimension to the assessment. Instead of manually drilling ice cores, the team used a 100-kilogram instrument hovering 20 metres above the surface, while the plane cruised along 100 metres above the ice at 240 km/h. The instrument emitted low-frequency electromagnetic signals, which penetrated the ice to provide accurate data on the actual sea ice thickness.
Having returned from their successful mission, the team is planning more surveys for 2011 and 2012.
