December 16, 2013
Arctic Sea Ice Levels Rise By 50 Percent This Fall
Lee Rannals for redOrbit.com - Your Universe Online
The European Space Agency’s (ESA) CryoSat satellite has delivered some good news about the Arctic sea ice this fall. New measurements taken by CryoSat show the volume of Arctic sea ice has significantly increased this fall, rising by about 50 percent compared to last year. Satellites have been showing a downward trend in the area of Arctic Ocean covered by ice over the past few decades, so the latest measurements are much welcomed news.
The actual volume of sea ice has been tough for scientists to determine because it moves around, which means thickness can change. CryoSat was designed to measure sea-ice thickness across the entire Arctic Ocean, allowing scientists to monitor the overall change in volume accurately for the first time.
ESA said about 90 percent of the increase is due to growth of multiyear ice, which survives through more than one summer without melting. This ice indicates a healthy Arctic sea-ice cover, and this year’s multiyear ice is on average about 20 percent thicker than last years.
“One of the things we’d noticed in our data was that the volume of ice year-to-year was not varying anything like as much as the ice extent – at least in 2010, 2011 and 2012,” said Rachel Tilling from the UK’s Centre for Polar Observation and Modeling, who led the study. “We didn’t expect the greater ice extent left at the end of this summer’s melt to be reflected in the volume. But it has been, and the reason is related to the amount of multiyear ice in the Arctic.”
Although it seems like these measurements should help add weight to a climate change skeptic’s argument, ESA says the latest intel doesn’t indicate a reversal in the long-term trend.
“It’s estimated that there was around 20,000 cubic kilometers (4,700 cubic miles) of Arctic sea ice each October in the early 1980s, and so today’s minimum still ranks among the lowest of the past 30 years,” said Professor Andrew Shepherd from University College London.
While the latest results are good for the Arctic Ocean, things are looking a little more grim on the other end of the world. Scientists at the American Geophysical Union said last week ice loss in Antarctica is occurring at a faster pace than previously thought. This team revealed how the West Antarctic Ice Sheet is showing a loss of nearly 100 cubic miles of ice per year.