Scientists with Europe’s Cryosat mission have been getting an extraordinary glimpse of the Great North.
The Cryosat team, led from University College London, has been watching the ebb and flow of Arctic sea ice with great precision.
The radar spacecraft was launched in 2010 to monitor changes in the thickness and shape of polar ice. For the past two years, scientists have been trying to make sense of the data. And this week, the team reported that Cryosat was transmitting back some unusual and unprecedented views. The images apparently show the seasonal growth and retreat of sea ice spanning the entire Arctic basin.
The BBC recently spoke to Prof Volker Liebig, the director of Earth Observation at the European Space Agency (ESA). He was quoted as saying, “The message is that Cryosat is working extremely well. Its data are very reliable and the measurements we have match reality. We now have a very powerful tool to monitor the changes taking place at the poles.”
According to reports, several satellites have already detailed the recent and rapid erosion of summer sea ice as the Arctic has warmed.
But the BBC says Cryosat’s innovation has been to provide a means to get at a figure for ice volume. This is a far more significant number in terms of understanding the long-term viability of the ice. To do this, the satellite carries one of the highest resolution synthetic aperture radars ever put in orbit. The instrument sends down pulses of microwave energy. These pulses bounce off both the top of the ice and the water in the cracks, or leads, which separate the floes. By measuring the difference in height between these two surfaces, scientists can, using a relatively simple calculation, work out the overall volume of the marine cover.
In addition to the announcement on sea ice, the Cryosat team also published a digital elevation model (DEM) of Greenland.
The massive island has also seen some rapid changes lately. Scientists say that it, too, is losing tens of billions of tonnes of its ice cover to the ocean each year.
The Cryosat update was timed to coincide with this week’s 50th anniversary of UK activity in orbit.
Back in April 1962, Britain launched its first satellite called the Ariel-1.
As part of the celebrations, current UK-based missions are being highlighted throughout the week.