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.
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