New elevation measurements will give researchers an unprecedented understanding of the thickness of sea ice, which will be used to help improve climate modeling and forecasts.
In 1984, there were 1.86 million square kilometers of old ice spread across the Arctic at its yearly minimum extent. In September 2016, there were only 110,000 square kilometers of old ice left.
Enough ice lines the coasts of Sweden and Finland in this natural-color image from March 5, 2010, that it is difficult to tell where the coast ends and the sea begins.