The world’s glaciers shrank by 2 percent between 2010 and 2020 alone, almost entirely due to higher air temperatures. Researchers from the University of Edinburgh found this out by misusing data from a satellite that actually measures sea ice and the polar ice sheets. Using a new technique, however, they were able to determine from the data from the ESA satellite CryoSat-2 that the world’s glaciers have lost around 2,720 gigatonnes of ice within just 10 years. That is two percent of their total volume. As much ice melts every year as would fit in a cube towering over Mont Blanc.
Preparation for special mission to glaciers
As the two explain, after the two ice sheets (Antarctica and Greenland), glaciers are the biggest contributors to sea level rise. At the same time, they are one of the most important sources of drinking water worldwide – for more than 1.3 billion people in Asia alone. Nevertheless, research into their shrinkage is limited, among other things because they are always located in areas that are difficult to access and so far there is no satellite mission dedicated specifically to this question. Livia Jakob and Noel Gourmelen have now succeededto quantify this ice retreat using data from the Earth observation satellite CryoSat-2. It was launched in 2010 and has been measuring the layers of sea ice and the ice sheets at the poles ever since.
The two have now determined not only how much ice the world’s glaciers have lost since 2010, but also through which processes. While warm air temperatures account for most of the decline, they attribute the rest to so-called ice runoff. This takes place on glaciers that end in the sea and the tip of which is melted off by warmer sea water. The Barents and Kara Seas in northern Russia, Patagonia in South America and the periphery of Antarctica are particularly badly affected by this process.
Thanks to her work, we now know more precisely how the atmosphere and oceans interact when ice is lost, says Gourmelen. Her work will also help to develop ESA’s planned Cristal Earth observation satellite, which will also measure glaciers in the future. Has been published the research work in den Geophysical Research Letters.
(my)
