USA Update News

Washington — The U.S. Coast Guard cutter Healy docked in Seward, Alaska, July 21 after a five-week scientific expedition sponsored by the U.S. National Aeronautics and Space Administration (NASA) amassed a wealth of data about the effects of climate change on Arctic seas and the polar ice cap.

The expedition was part of NASA’s $10 million, multiyear project formally known as Impacts of Climate Change on the Eco-systems and Chemistry of the Arctic Pacific Environment, or ICESCAPE for short. ICESCAPE is an interdisciplinary project that combines field-based observations of Arctic Ocean biology and biogeochemistry, such as those conducted aboard the Healy, with satellite sensing and numerical modeling to produce a better understanding of the ecosystem of the Arctic Ocean.
ICESCAPE’s central mission is to determine the impact of climate change, caused by both human and natural factors, on the ecology and biogeochemistry of the Arctic Ocean.

Such research has gained increased importance with the retreat of the summer ice cap and the resulting decline of Arctic sea ice and an earlier, longer lasting melting season. These changes, already evident in the Beaufort and Chukchi seas that lie north of the Bering Strait, have consequences for the entire ecosystem of the Arctic Ocean.

“The Arctic Ocean has undergone some pretty big changes in recent decades,” said Kevin Arrigo of Stanford University in an interview with America.gov. He was the chief scientist aboard Healy during its mission. “Biological productivity has ratcheted up, and the timing of many key events is shifting.” That is significant, he said, because many animals key their migration to be in the Arctic when it is at its biologically most productive.

After departing from the Aleutian Islands port of Dutch Harbor June 15, the Healy crossed through the Bering Strait, traveled across the southern Chukchi Sea, and then headed into the Beaufort Sea along the ocean shelf of northern Alaska on an expedition that totaled 5,430 nautical miles, or slightly more than 10,000 kilometers.

During the Healy’s five-week deployment, 50 scientists in disciplines as varied as oceanography, microbiology, chemistry and optical physics took samples both within and beneath the thick sea ice, captured more than 1.5 million digital images of phytoplankton cells living in the ocean, and analyzed water samples to measure temperature as well as biological and optical properties.

“I can’t imagine things going better than they did for us during ICESCAPE,” Arrigo said. “We managed to make physical, chemical and biological measurements at 140 stations, about twice the number we expected to be able to complete.” The sampling stations covered an expanse from the coast of Alaska westward to the U.S.-Russian border, and from the Bering Strait north to Barrow, Alaska.

“There undoubtedly will be many other discoveries to make, and many papers to write,” Arrigo said. “By any measure, ICESCAPE 2010 was an unqualified success.”