NASA's IceBridge Seeking New View of Changing Sea Ice

This year scientists working on NASA's Operation IceBridge, a multi-year airborne science mission to study changing ice conditions at both poles, debuted a new data product with the potential to improve Arctic sea ice forecasts.

Using new data processing techniques, IceBridge scientists were able to release an experimental quick look product before the end of the 2012 Arctic campaign. The main challenge faced when producing data for seasonal forecasts is the time needed to crunch the numbers, something that has in the past taken IceBridge scientists more than six months to do after the data was collected in the spring. This is too late to use for Arctic sea ice forecasts of the annual seasonal minimum, which takes place in September.

The new product could potentially be used in seasonal sea ice forecasts in the future. "The community is excited about it," said IceBridge science team co-lead Jackie Richter-Menge of the U.S. Army Corps of Engineers Cold Regions Research Laboratory, Hanover, N.H. "We're hoping to build on this season's momentum and interest."

Scientists have been keeping an eye on Arctic sea ice in recent years because it is changing and they want to understand what those changes might mean. Arctic sea ice grows and recedes in a seasonal pattern, with a maximum coverage in March and a minimum in September. These high and low points vary from year to year, but there is a clear trend toward smaller minimums that mean more open water in the Arctic each summer and fall. This decrease in ice is already affecting ocean and terrestrial life in the Arctic, accelerating warming in the region and leading to economic and social changes.

"Sea ice is a sensitive indicator of a changing climate," said NASA researcher Nathan Kurtz at NASA's Goddard Space Flight Center, Greenbelt, Md. It can also act as a feedback to warming in the Arctic. Because ice is much lighter in color than ocean water it has a higher albedo, meaning it reflects more sunlight than water. "A loss of sea ice can cause the Earth as a whole to warm," Kurtz said. The loss of sea ice has also been linked to shifts in weather patterns and distribution of nutrients in the ocean.

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NASA Continues Critical Survey of Antarctica's Changing Ice

WASHINGTON -- Scientists with NASA's Operation IceBridge airborne research campaign began the mission's third year of surveys this week over the changing ice of Antarctica.

Researchers are flying a suite of scientific instruments on two planes from a base of operations in Punta Arenas, Chile: a DC-8 operated by NASA and a Gulfstream V (G-V) operated by the National Science Foundation and the National Center for Atmospheric Research. The G-V will fly through early November. The DC-8, which completed its first science flight Oct. 12, will fly through mid-November.

Ninety-eight percent of Antarctica is covered in ice. Scientists are concerned about how quickly key features are thinning, such as Pine Island Glacier, which rests on bedrock below sea level. Better understanding this type of change is crucial to projecting impacts like sea-level rise.

"With a third year of data-gathering underway, we are starting to build our own record of change," said Michael Studinger, IceBridge project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "With IceBridge, our aim is to understand what the world's major ice sheets could contribute to sea-level rise. To understand that you have to record how ice sheets and glaciers are changing over time."

IceBridge science flights put a variety of remote-sensing instruments above Antarctica's land and sea ice, and in some regions, above the ocean floor. The G-V carries one instrument: a laser-ranging topography mapper. The DC-8 carries seven instruments, including a laser altimeter to continue the crucial ice sheet elevation record begun by the Ice, Cloud and land Elevation Satellite (ICESat) mission, which ended in 2009. The flying laboratory also will carry radars that can distinguish how much snow sits on top of sea ice and map the terrain of bedrock below thick ice cover.

While scientists in recent years have produced newer, more detailed data about the ice sheet's surface, the topography of the rocky surface beneath the ice sheet remains unknown in many places. Without knowing the topography of the bedrock, it is impossible to know exactly how much ice sits on top of Antarctica.

A gravimeter aboard the DC-8 will detect subtle differences in gravity to map the ocean floor beneath floating ice shelves. Data on bathymetry, or ocean depth, and ocean circulation from previous IceBridge campaigns are helping explain why some glaciers are changing so quickly.

Flights take off from Punta Arenas and cross the Southern Ocean to reach destinations including West Antarctica, the Antarctic Peninsula and coastal areas. Each lasts 10 to 11 hours.