On 21 June 2011, the first sea-ice thickness map of the Arctic was presented by the European Space Agency (ESA) at the Paris Air and Space Show. From an altitude of just over 700 km and reaching unprecedented latitudes of 88º ESA's CryoSat mission has spent the last seven months delivering precise measurements to determine changes in the thickness of Earth's ice, which is necessary to fully understand how climate change is affecting the fragile Polar Regions.

It is the first fully processed map from Europe's new Cryosat spacecraft.

It only covers the months of January and February, but the UK team behind the data says it can now roll out the information on a continuous basis.

CryoSat measures the height of the sea ice above the water line, known as the "freeboard", to calculate the thickness. The measurements used to generate this first map of the Arctic were from January and February 2011, as the ice approaches its annual maximum. The data are exceptionally detailed and considerably better than the mission's specification. They even show lineations in the central Arctic that reflect the ice's response to wind stress.

The extent of Arctic sea-ice has become a major issue in recent years, with summer melting appearing to outstrip what many climate models had predicted.

But a proper assessment of the status of the sea-ice requires knowledge also about its thickness - something scientists have only recently had the tools to measure from space.

"A new mission is always risky. There's quite a long wait and then everyone gets to see if it really can deliver, explained the Cryosat mission's principal investigator, Professor Duncan Wingham.

"What's really nice about these results is that they show not only that the hardware is really excellent - which we already knew - but that it can deliver the geophysical information we need too.

"It's a credit to the teams at ESA and UCL who have worked really hard and I'm very happy with these new results." Professor Duncan Wingham said

"Some years the wind will push the ice out of the way or pile it up, and it may look from the area coverage like it's all melted," "But it's only when you combine the area coverage information with the thickness information that you get the product - volume. And that's what you really need to know to answer the question about melting," he also told BBC News.

Prof. Duncan Wingham from University College London first proposed the CryoSat mission to ESA in 1998. The loss of the original CryoSat satellite in 2005 as a result of a launch failure delayed the mission.

Nevertheless, the launch of the replacement satellite in April 2010 has resulted in these first maps of ice thickness. They clearly demonstrate that CryoSat is a mission of excellence and will greatly advance polar science.

The results were presented at the Le Bourget air and space show by Volker Liebig, ESA's Director of Earth Observation Programmes, Duncan Wingham and René Forsberg from the National Space Institute at the Technical University of Denmark.

"It has taken about ten years to convert the initial proposal into a flying mission: ten years of hard work and dedication from a core team of less than a hundred people, ably assisted with crucial expertise from a few hundred more."

ESA's CryoSat Mission Manager, Tommaso Parrinello, added, "These first results are very exciting as we begin to see the mission's potential realised.

"The coming months will be dedicated to completing the picture to gain better insight into how polar ice is changing."

Climate Change London