An important goal of the European Space Agency’s CryoSat mission is to measure, from space, changing sea-ice thickness over time. Yet, a remarkable feature about Arctic sea-ice is that you actually rarely see it – at least when you look at it from above. So, why is this?
A lonely ice floe surrounded by a field of rubble ice. (ESA)
Arctic sea-ice is usually blanketed with snow and frost, masking the ice and ocean below. Even when walking on sea ice it rarely feels like ice – it’s more like a snow field. I’m guessing that for someone who has never travelled to the Arctic, they would be hard-pressed to identify a sea ice ‘landscape’ from most of the pictures I’ve taken out of the Twin Otter aircraft window over the past days. Certainly, the smooth dark-blue or semi-transparent ice we sometimes see and even skate on in the Netherlands is something completely diﬀerent.
A thicker ice floe in the background contrasts with the smooth recently frozen ice channel in front. (ESA)
It is the texture of the surface that provides clues as to what lies beneath. Sea ice experts I’ve met will tell you that each ice floe or ...