Scientists at the European Space Agency Wednesday presented evidence that levels of arctic sea ice reached an all-time low this spring, according to data collected by the ESA's Cryosat satellite.
The measurements are on trend with what Cryosat has observed throughout the first three years of its mission. Launched in 2010, the satellite uses radar to measure the difference between the top height of the ice and the top height of water in cracks between the ice sheets. Scientists use this radar data to calculate the thickness and volume of the ice.
"Cryosat continues to provide clear evidence of diminishing Arctic sea ice," Professor Andrew Shephard said in an address at the Living Planet Symposium in Edinburgh, Scotland.
"From the satellite's measurement we can see that some parts of the ice pack have thinned more rapidly than others, but there has been a decrease in the volume of winter and summer ice over the past three years."
At the end of last winter, there was less than 15,000 cubic kilometers of sea ice, he explained. That measurement is lower than ever previously measured, and less than half of the volume of thirty years ago. It indicates that ice is not expanding during the winter months.
"Now that we have three years of data, we can see that some parts of the ice pack have thinned more rapidly than others. At the end of winter, the ice was thinner than usual. Although this summer's extent will not get near its all-time satellite-era minimum set last year, the very thin winter floes going into the melt season could mean that the summer volume still gets very close to its record low," Shepard told the BBC.
The researchers will have to wait until October, when the ice starts to refreeze, to determine if the ice reached a new low this summer.