UK team heads for Arctic to check satellite's accuracy

Wednesday 17th Aug 2011 by theWeather Club

Measurements are everywhere, they are the foundations on which all the sciences are based and meteorology is no exception. However one of the challenges facing this discipline is that unlike the laboratory sciences, many of the measurements are remotely gathered, often by instruments speeding around the globe in near Earth orbit. It of course begs the question how do you know, they’re working? That they have survived their somewhat bumpy deployment and are gathering, analysing and transmitting the data back correctly? Sometimes you just have to go and check, but this is often easier said than done.

A team of researchers from University College London (UCL) has just left the UK for the Arctic to test how well the CryoSat-2 satellite launched by the European Space Agency (ESA) is performing. CryoSat-2 was launched in April 2010 and is designed to measure changes in ice thickness at the poles with unprecedented accuracy. But researchers need to test how well its radar can see through snow. So, they're making measurements on Earth to compare them with measurements taken by CryoSat-2 from space.

The team will be taking radar equipment similar to that onboard the actual satellite, on a sledge onto the sea ice. While there they will study snow properties as well as taking measurements with the radar. Aircraft from ESA and NASA will fly over them taking measurements with radars and lasers to compare what they see on the ice with what CryoSat-2 sees from space.

The CryoSat-2 radar is designed to see through clouds and cold, dry snow. The thing is that sea ice is often covered by a layer of snow, but that snow isn't always cold and dry, its properties can change from area to area. So the researchers will investigate the snow cover in different places and look at how changes in its properties, such as density and wetness, affect the radar's ability to see through it to the ice beneath. The team is made up of scientists from the Centre for Polar Observation and Modelling (CPOM) at UCL, which first had the idea for CryoSat-2 over a decade ago.

To get to the sea ice, the team is flying from the UK to Ottawa, then to Resolute, on to Alert in northern Canada and then a small plane to get to the sea ice they want to study. All in all on the journey will take about five days, and end on a slab of ice floating in the Arctic Ocean. Suddenly that everyday commute to the office looks a little less taxing.