CU-Boulder researchers are monitoring dwindling sea ice in the Arctic.
With ice watchers at the National Snow and Ice Data Center reporting unprecedented meltback of Arctic Ocean ice this summer, ice forecasters at the University of Colorado at Boulder say the worst is yet to come.
In a release posted on-line Aug. 16, UCB researchers with the Arctic Regional Ice Forecasting System group say the lack of thick multi-year ice makes it virtually certain that September will deliver the all-time minimum for polar ice in the Arctic.
What are the odds? It’s grim — 92 percent. Here’s more:
The researchers, who forecast in April a 33 percent chance the September minimum of sea ice would set a new record, dramatically revised their prediction following a rapid disintegration of sea ice during July, said Research Associate Sheldon Drobot of CU-Boulder’s Colorado Center for Astrodynamics.
“During the first week in July, the Arctic sea ice started to disappear at rates we had never seen before,” said Drobot, who leads CCAR’s Arctic Regional Ice Forecasting System group in CU-Boulder’s aerospace engineering sciences department.
“We have been seeing a sharp decline in thicker, multi-year ice that has survived more than one melt season,” said CCAR Research Associate James Maslanik. “This has been replaced in many areas by a thin, first-year layer of ice as well as by younger, thinner types of multi-year ice. The thinner ice just does not have the mass to withstand the effects of warming climate.”
Some perspective. Sea ice serves as habitat for polar bears, walrus and seals. Fish and other creatures thrive along its edge and beneath its surface. Alaska Native, Canadian Inuit and Russian hunters all use sea ice as a platform to harvest food. The formation of shore ice — buttressed by off-shore floes — protects coastal villages from damaging fall and winter storms.
Shrink the ice, and you shrink the habitat, expose villages to erosion, stress polar bears, make life harder for indigenous people. For a vivid discussion of how the retreating ice cut off food-gathering for subsistence walrus hunters in Wainwright, read Retreat of the Ice in the Aug. 16 Anchorage Daily News.
(Shrinking ice cover also may make it more possible for expanded shipping across the Arctic, although this issue is far more complex than one might guess. In some cases, lack of an ice pack might make polar shipping more hazardous.)
In September, 2005, the area covered by at least 85 percent ice shrank to the lowest extent ever recorded by satellites — about 2.15 million square miles. In 2006, Arctic ice didn’t quite shrink as much, but did end September with the second smallest ice extent on record.
What do the forecasters at UC-Boulder say? Expect ice to cover only 1.96 million square miles — with a 25 percent possibility of 1.88 million square miles and five percent chance of 1.75 million square miles.
Arctic sea ice is “one of the better predictors of climate change on Earth,” Drobot said. “There will probably be about two-thirds as much sea this September as there was 25 years ago, a good indication that something significant is happening with the climate.”