Arctic sea ice: a chain reaction

Dr Thomas Krumpen, sea ice physicist and expert for satellite analyses at the Alfred Wegener Institute.

Sea ice

Application of satellite data

Arctic Ocean


For the past several years, the sea ice in the Arctic has melted more and more intensively during the summer months. To determine whether, and if so, how this trend will continue, we first need to better understand the processes involved in the formation and disappearance of sea ice. With that goal in mind, we at AWI are exploring the thickness and surface conditions of Arctic sea ice. We measure both properties in several key regions of the Arctic Ocean with autonomous buoys, on helicopter and aircraft measurement campaigns and with the help of satellites.

Our collected data are now considered one of the most important reference data set on the development of Arctic sea-ice cover worldwide. Those surveys indicate that the thickness of sea ice leaving the Arctic Ocean towards the North Atlantic has steadily decreased since 2001. There are several reasons for the observed thinning: First, rising air and water temperatures in the Russian Arctic are causing large areas of sea ice to melt in the summer, and the formation of new ice in the fall is starting later than it used to. In addition, sea-ice drift is accelerating. This means that the ice floes – driven by wind and ocean currents – need less time to cross the Arctic and they have less time to grow. As a result, sea ice today is much thinner, younger and more mobile than it used to be, which means that wind and waves can easily break it and are even able to mix the ocean’s surface water. This may allow warm water to rise from the depths, which then additionally harms the sea ice from below.  

At the AWI, we are investigating how all these processes interact and, if necessary, reinforce each other in their effect. Our goal is to predict the future development of the Arctic sea-ice cover as accurately as possible. After all, it’s not only one of the most important elements in the Earth’s climate system, but also a unique habitat that is shrinking.