[meteorite-list] NASA'S Operation Icebridge Resumes Flights Over Antarctica

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 12 Oct 2012 13:15:57 -0700 (PDT)
Message-ID: <201210122015.q9CKFwVK000866_at_zagami.jpl.nasa.gov>

Oct. 12, 2012

Steve Cole
Headquarters, Washington
stephen.e.cole at nasa.gov
202-358-0918

George Hale
Goddard Space Flight Center, Greenbelt, Md.
george.r.hale at nasa.gov
301-614-5853


RELEASE: 12-360

NASA'S OPERATION ICEBRIDGE RESUMES FLIGHTS OVER ANTARCTICA

WASHINGTON -- Scientists and flight crew members with Operation
IceBridge, NASA's airborne mission to study Earth's changing polar
ice, are beginning another campaign over Antarctica. Now in its
fourth year, IceBridge's return to the Antarctic comes almost a year
after the discovery of a large rift in the continent's Pine Island
Glacier.

The first science flight of the campaign began Friday at 8 a.m. EDT
when NASA's DC-8 research aircraft left Punta Arenas, Chile, for an
11-hour flight that will take it over the Thwaites Glacier in west
Antarctica. This year, IceBridge will survey previously unmeasured
areas of land and sea ice and gather further data on rapidly changing
areas like Pine Island Glacier. The IceBridge Antarctic campaign will
operate out of Punta Arenas through mid-November.

Several of IceBridge's planned flights focus on previously unmeasured
ice streams feeding into the Weddell Sea. These flights will gather
data on what lies beneath these ice streams, something vital for
understanding how changing conditions might affect the flow of ice
into the ocean and sea-level rise.

"We have added surveys of ice streams flowing into the Ronne and
Filchner ice shelves," said IceBridge project scientist Michael
Studinger at NASA's Goddard Spaceflight Center in Greenbelt, Md.
"This is something we haven't done before."

The large crack in Pine Island Glacier's floating ice shelf has been
the focus of worldwide attention as it has grown. The ice shelf now
threatens to calve, or break off, a large iceberg into Pine Island
Bay in the Amundsen Sea. Researchers have been using imagery from
NASA's Aqua and Terra spacecraft and synthetic aperture radar data
from the German Aerospace Center's TerraSAR-X satellite to monitor
the rift since its discovery last year.

IceBridge also will gather data on sea ice in the Weddell and
Bellingshausen seas. Because of geographical differences, Antarctic
sea ice behaves differently from ice in the Arctic and presents
unique challenges.

"Sea ice in the Antarctic is a very different physical system,"
Goddard sea ice researcher Nathan Kurtz said.

Ocean currents, precipitation patterns and the shape of land masses
are just a few of the differences. Instead of compacting ice against
land like in the Arctic basin, currents in the Southern Ocean push
much of it farther out to sea. Also, the Antarctic averages more
snowfall, which weighs sea ice down and allows ocean water into the
bottom layer of the snow on top of the sea ice. The Antarctic has
more frequent strong wind events and large temperature swings than
the Arctic, which causes layers of ice to form in snow cover. Both of
these factors make getting accurate readings of snow on top of sea
ice challenging.

Arctic sea ice extent and volume reached record lows this year, but
Antarctic sea ice volume has been holding steady and the extent has
been increasing. Predictive models have a hard time pinpointing what
Antarctic sea ice might do under a warming global climate. Having
more data to work with could make these models more useful. Further
observations will give researchers more data on how Antarctic sea ice
changes over time.

"This is why having observations is really important," Kurtz said. "We
want to make sure these models are getting the physics right.

IceBridge will gather information on many different aspects of land
and sea ice using a variety of scientific sensors onboard the DC-8.
These instruments include a laser altimeter to measure surface
elevation changes, various radar instruments for determining snow
depth and ice thickness, a gravimeter that will gather data on the
size and shape of water cavities under ice shelves, and a digital
camera instrument that takes high-resolution images useful for
building maps and digital elevation models of the ice.

By flying previously surveyed tracks in rapidly changing areas like
Pine Island Glacier, IceBridge is building on a legacy of
measurements started by NASA's ICESat satellite that will continue
with the launch of ICESat-2 in 2016.

"This area is changing so rapidly we need to survey every year,"
Studinger said.

In addition, IceBridge will fly along tracks for the European Space
Agency's ice-monitoring satellite, CryoSat-2.

This year's campaign also will see visits to IceBridge by school
teachers. Two English-speaking Chilean science teachers will meet
with IceBridge scientists and instrument operators this month and
ride on a survey flight to learn more about polar science research
with the goal of using their new knowledge to better engage and teach
students.

The IceBridge project science office is based at Goddard. The DC-8 is
based at NASA's Dryden Aircraft Operations Facility in Palmdale,
Calif.
For more information, images and video of Operation IceBridge, visit:

http://www.nasa.gov/icebridge

For more information about ICEsat-2, visit:

http://icesat.gsfc.nasa.gov/icesat2
        
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Received on Fri 12 Oct 2012 04:15:57 PM PDT