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

[Ron Baalke]

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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