A new study highlights how extreme snowfall events significantly alter the amount of ice lost by the West Antarctic Ice Sheet. A team of scientists from British Antarctic Survey, along with colleagues from the University of Leeds and Utrecht University, calculated the amount of ice lost from West Antarctica and the drivers behind this. Changes to the snowfall in the region greatly alters the ice lost significantly altering the sea level rise contribution during this time.
The research, led by Dr Benjamin Davison at the University of Leeds, calculated the “mass balance” of the Amundsen Sea Embayment, the fastest changing region in Antarctica. This describes the balance between the amounts of snow and the ice gained due to snowfall and how much ice is lost through calving events, where icebergs form at the end of a glacier and drift out to sea. When calving happens faster than the ice is replaced by snowfall, then the region loses mass overall and contributes to global sea level rise. Similarly, when snowfall supply drops, the area can lose mass overall and contribute to sea level rise.
Using climate models of the region, scientists found that the Amundsen Sea Embayment had experienced several extreme snowfall events. Between 2009 and 2013, the models revealed a period of persistently low snowfall, or a “snow drought”. The lack of nourishing snowfall starved the ice sheet and caused it to lose ice, therefore contributing about 25% more to sea level rise than in years of average snowfall.
Read more at British Antarctic Survey
Photo Credit: NASA ICE/James Yungel via Wikimedia Commons
