Arctic Sea Ice Half as Thin as in 2001

Large swaths of Arctic sea ice are only half as thick as they were six years ago, according to new research from the Alfred Wegener Institute for Polar and Marine Research.

Scientists aboard the research vessel Polarstern report large sections of sea ice in the central Arctic Basin only three feet (about one meter) thick this summer, about 50 percent thinner than they were in 2001. The thickness of Arctic sea ice has been shrinking since 1979, and computer models indicate the Arctic could be completely ice-free in less than 50 years if the climate continues to warm.

Researchers collecting data from the Polarstern for the past two-and-a-half months also report finding a large number of melt ponds on Arctic ice as well as high concentrations of fresh meltwater in the ocean.

"The ice cover in the North Polar Sea is dwindling, the ocean and the atmosphere are becoming steadily warmer, the ocean currents are changing," said chief scientist Ursula Schauer, who is participating in the Polarstern expedition along with 50 scientists from China, Germany, Finland, France, Japan, the Netherlands, Russia, Spain, Switzerland and the U.S. "We are in the midst of a phase of dramatic change in the Arctic, and the International Polar Year 2007-2008 offers us a unique opportunity to study this dwindling ocean in collaboration with international researchers."

The Polarstern expedition is studying an area that stretches from the continental shelves of the Barents Sea, Kara Sea and Laptev Sea to areas of Nansen Bay, Amundsen Bay and Makarow Bay. Researchers on board the ship have measured water temperature, ocean currents and salinity at more than 100 sites throughout the study area. They have found that both temperatures and salinity levels have changed by small amounts, but that those changes are measurable down to great depths, meaning that enormous volumes of water are being affected.

Biologists aboard the Polarstern are also studying plants and animals that live in and below the Arctic ice. They are concerned that many of these species could become extinct if the sea ice disappears.

Earlier this month, scientists with the U.S. National Snow and Ice Data Center reported that the extent of Arctic sea ice had shrunken to 1.63 million square miles, far below the previous record of 2.05 million square miles set in September 2005.

Alfred-Wegener Institute for Polar and Marine Research: "The Sea Ice is Getting Thinner." URL: (http://www.awi.de/en/news/press_releases/detail/item/the_sea_ice_is_getting_thinner_a_closer_look_at_the_climate_and_ecosystem_of_the_arctic_ocean/)