Arctic sea ice volume bounced by 41% in 2013


Global warming dangers are lurking, but all is not as black and white as is portrayed because a recent study has revealed that volume of sea ice in Arctic increased by a third after the summer of 2013 as the unusually cool air temperatures prevented the ice from melting.

Researchers from UCL and University of Leeds revealed through their study that the ice in the Northern hemisphere is more sensitive to changes in summer melting than it is to winter cooling, a finding which will help researchers to predict future changes in its volume.

The study, published in Nature Geoscience, used 88 million measurements of sea ice thickness recorded by the European Space Agency’s CryoSat-2 mission between 2010 and 2014. Researchers showed that there was a 14 per cent reduction in the volume of summertime Arctic sea ice between 2010 and 2012, but the volume of ice jumped by 41 per cent in 2013 (relative to the previous year), when the summer was 5 per cent cooler than the previous year.

Lead author and PhD student, Rachel Tilling from the Centre for Polar Observation and Modelling (CPOM), UCL Earth & Planetary Sciences said that the relatively cooler 2013 allowed thick sea ice to persist northwest of Greenland because there were fewer days when it could melt.

This means that even though climate and other sea ice models suggest that the volume of sea ice in the region is in long term decline, there is still scope for recovery by a significant amount if the melting season is cut short.

Studies have shown that there has been a steady decline in volume of Arctic ice since the late 1970s; however, the accurate readings about the loss were difficult to obtain before CryoSat-2.

When compared to ~772,000 readings from an airborne laser, 430 measurements from electromagnetic sensors and 80 million upward-looking sonar observations, the team found that CryoSat’s measurements of sea ice thickness agreed to within 2mm.

Co-author Professor Andy Shepherd, Professor of Earth Observation at UCL and at the University of Leeds, believes that their findings take researchers one step closer to making reliable predictions about how long the sea ice will last. Though there has been a jump in volume and this indicates that the region is unlikely to be ice free this summer, there will be increase in temperatures in future that will lead to further melting.

“Our goal is to make sure we do not lose this unique capability to monitor Arctic sea ice when the mission ends”, Professor Shepherd added.

The team now plan to use CryoSat-2’s measurements of changing sea ice thickness to help improve the models that are used to predict future climate change, and also to assist maritime activities in the Arctic region, which can be dangerous and costly to navigate.