Researchers aboard NASA's P-3 research aircraft left the agency's
Wallops Flight Facility in Wallops Island, Va., March 10 for Greenland
to begin a new season of collecting data on Arctic land and sea ice.
The mission, known as Operation IceBridge, is to gather data on
changes to polar ice and maintain continuity of measurements between
NASA's Ice, Cloud and Land Elevation Satellite (ICESat) missions. The
original ICESat mission ended in 2009, and its successor, ICESat-2, is
scheduled for launch in 2017.
By flying yearly campaigns, IceBridge provides valuable data on
rapidly changing areas of polar land and sea ice. Flights run through
May 23 from Thule Air Base and Kangerlussuaq, Greenland, with a
week-long deployment to Fairbanks, Alaska.
Over the past five years, IceBridge has surveyed large portions of
the Greenland and Antarctic ice sheets, as well as sea ice in both polar
regions. IceBridge data have been used to build detailed maps of
bedrock in Greenland and Antarctica, calculate changes in Arctic sea ice
thickness and volume, and improve our understanding of the rate at
which glaciers in Greenland are flowing into the sea.
The first part of the campaign will focus on sea ice in the Arctic
Ocean north of Greenland and in the Beaufort and Chukchi seas north of
Alaska. As in the past two years, IceBridge will provide data on ice
thickness to help sea ice researchers develop more accurate seasonal
Arctic sea ice models.
The remainder of the campaign will turn to measuring ice surface
elevation and thickness at many of the Greenland Ice Sheet's outlet
glaciers, which are channels of ice that flow from an ice sheet,
constrained on its sides by bedrock. The surface elevation measurements
taken by IceBridge's laser altimeter, the Airborne Topographic Mapper,
will provide scientists data on how the ice sheet is changing and give a
useful benchmark for ICESat-2.
Radar instruments such as the Multichannel Coherent Radar Depth
Sounder, which is operated by the Center for Remote Sensing of Ice
Sheets at the University of Kansas in Lawrence, Kan., will peer beneath
the surface to collect the data on ice thickness and sub-ice terrain,
internal layering in the ice sheet and snow depth.
The P-3 research aircraft's extensive instrument suite features a new component this year –
a spectrometer that measures ice albedo, or reflectivity.
"A small change in albedo over the entire Arctic could have a
significant effect on how much heat is absorbed by the surface," said
Nathan Kurtz, a sea ice scientist at NASA's Goddard Space Flight Center
in Greenbelt, Md. This year's flights will serve as a preliminary test
for the instrument.
Throughout the campaign, the IceBridge team will coordinate its
efforts with other research groups working in the region. Researchers on
the surface will study sea ice and snow thickness near Barrow, Alaska,
in the Canadian Basin and just north of Greenland. Measurements in these
areas will later be used to further verify the accuracy of IceBridge's
snow radar instrument, particularly in areas with rough ice surfaces.
According to Jackie Richter-Menge, sea ice scientist with the U.S.
Army Corps of Engineers Cold Regions Research and Engineering Laboratory
in Hanover, N.H., snow radar works well on ice that has not been
deformed. Ice with a rougher surface can scatter radar waves, making the
returning signal harder to interpret.
The IceBridge team also will work with the CryoVEx (CryoSat-2
Validation Experiment) team, which operates a campaign to verify
measurements made by the European Space Agency's ice-monitoring
satellite, CryoSat-2, in orbit since 2010. The IceBridge team plans to
fly directly beneath the orbit of CryoSat-2 around the same time the
satellite passes overhead to compare measurements. Researchers from the
European Space Agency, York University in Toronto, Canada, and the
Technical University of Denmark also will be flying airborne instruments
to measure ice and snow.
"It's really exciting to have all of these people working together,"
said Richter-Menge. "It shows how interested everyone is in advancing
these measurements."
Three high school science teachers from the United States, Denmark
and Greenland also will join IceBridge and fly with the team to get
first-hand experience and knowledge they can bring back to their
classrooms. These teachers come to IceBridge through partnerships with
the U.S.-Denmark-Greenland Joint Committee and PolarTREC, a U.S.-based
program that pairs teachers with polar research expeditions.
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