Isabella Velicogna and John Wahr, both from the University of Colorado ,
Boulder, conducted the study.gov/home

For more information about Grace on the Web, visit:

http://www.
For information about NASA and agency programs on the Web, visit:

http://www.

temperate antarctic

4 millimeters (. Because ice sheets are a large source of uncertainties in
projections of sea level change, this represents a very important step toward
more accurate prediction, and has important societal and economic impacts.edu/grace

http://www. The study revealed Saturn
acts as a diffuse mirror for solar X-rays .

spri arctic

"
Massive solar explosions called flares often accompany coronal mass
ejections, which emit solar material and a magnetic field.

It includes information about the natural environment, environmental problems, and scientific activities specific to the Polar Regions.

glaciology doherty

Even as the research appeared to solve one mystery, the source of Saturn's
X-rays, it fueled long standing questions about magnetic fields.

arctic nsf

Most of the mass loss came from the West
Antarctic ice sheet.
The findings stem from the first observation of an X-ray flare reflected
from Saturn's low-latitudes, the region that correlates to Earth's equator and
tropics.

nsf nsidc

WASHINGTON, Scientists were able to conduct the
first-ever gravity survey of the entire Antarctic ice sheet using data from
the joint NASA/German Aerospace Center Gravity Recovery and Climate Experiment
(GRACE). To track these changes, GRACE measures micron -
scale variations in the 220 kilometer (137 mile) separation between the two
satellites, which fly in formation.
"The bigger the planet and nearer to the sun, the more solar photons it
will intercept; resulting in more reflected X-rays.

spri resesarch

That is about how much water the United States consumes in three months (a
cubic kilometer is one trillion liters; approximately 264 billion gallons of
water).
Dr. "These
results imply we could use giant planets like Jupiter and Saturn as remote-
sensing tools. Of the three
magnetic planets in our solar system, Jupiter and Earth emit two general types
of X-rays, auroral emissions from polar regions and disk emissions from low
latitudes.
Letters.html

collaborations temperate

csr., led the study team. No research has observed unambiguous signatures of auroral X-ray
emissions on Saturn. The Smithsonian Astrophysical
Observatory controls science and flight operations from the Chandra X-ray
Center in Cambridge, Mass.

respected lamont

They demonstrated for the first time that
Antarctica's ice sheet lost a significant amount of mass since the launch of
GRACE in 2002. GeoForschungsZentrum Potsdam (GFZ), Potsdam, Germany,
is responsible for German mission elements.de/grace

organising antarctic

It is twice as far from Earth as Jupiter.
Bhardwaj is working at MSFC as a National Research Council scholar. MSFC
manages the Chandra program for NASA's Science Mission Directorate in
Washington.

climatology meteorology

"Antarctica is Earth's largest reservoir of fresh water ," Velicogna said. GRACE is able to overcome these issues, surveying
the entire ice sheet, and tracking the balance between mass changes in the
interior and coastal areas.
GRACE is managed for NASA by the Jet Propulsion Laboratory (JPL),
Pasadena, Calif. The results will appear in this week's issue
of Science."
The research appeared in the May 10, 2005 issue of Astrophysical J.

researches respected

gfz-potsdam .

secretariat spri

The Antarctic mass loss findings were enabled by the ability of the
identical twin GRACE satellites to track minute changes in Earth's gravity
field resulting from regional changes in planet mass distribution.5 times larger than Earth." Bhardwaj said.

sintef climatology

This comprehensive study found the ice sheet's mass has decreased
significantly from 2002 to 2005. As
more GRACE data become available , it will become feasible to search for
longer-term changes in the rate of Antarctic mass loss," she said. Previous studies revealed Jupiter, with
a diameter 11 times that of Earth, behaves in a similar fashion.

cnr temperate

This represents a change of about 0. "It is interesting to note that even
as research solves some mysteries, it confirms there is much more we have to
learn.

organising cnr

Measuring variations in Antarctica 's ice sheet mass is difficult because
of its size and complexity.utexas. Anil Bhardwaj, a planetary scientist at NASA's Marshall Space Flight
Center (MSFC), Huntsville, Ala. By reflecting solar activity back to us, they could help us
monitor X-ray flaring on portions of the sun facing away from Earth 's space
satellites.nasa.

nsidc climatology

NASA Mission Detects Significant Antarctic Ice Mass Loss

The researchers
found Antarctica's ice sheet decreased by 152 (plus or minus 80) cubic
kilometers of ice annually between April 2002 and August 2005. Saturn is
about 9.

wegener meteorites

The estimated mass loss was enough to raise global sea level
about 1.
"We were surprised to find no clear evidence of auroral X-ray emissions
during our observations," Bhardwaj said., was the prime
development contractor for the observatory .

This category includes web sites about the natural, scientific, and environmental aspects of the Polar Regions.

climatology nsidc

016 inches) per
year to global sea level rise. Mass
movement of ice, air, water and solid earth reflect weather patterns, climate
change and even earthquakes.gov/home/index.

climatology spri

For information about NASA and agency programs on the Web, visit:

http: //www.

NASA's Chandra Finds Saturn Reflects X-rays From Sun

Northrop Grumman of Redondo Beach, Calif .

glaciology meteorology

"The GRACE mission is unique in its ability to measure mass changes directly
for entire ice sheets and can determine how Earth's mass distribution changes
over time. The University of Texas Center for Space Research has overall
mission responsibility. WASHINGTON, When it comes to mysterious X-rays from
Saturn, the ringed planet may act as a mirror, reflecting explosive activity
from the sun, according to scientists using NASA's Chandra X-ray Observatory.

spri nsidc

"Combining GRACE data with data from other instruments such as NASA's Ice
Cloud and land Elevation Satellite, radar and altimeters that are more
effective for studying individual glaciers is expected to substantially
improve our understanding of the processes controlling ice sheet mass
variations," Velicogna said . The research team also included Ron Elsner of MSFC; Hunter Waite of
the University of Michigan, Ann Arbor; Randy Gladstone of the Southwest
Research Institute, San Antonio, Texas; Thomas Cravens of the University of
Kansas, Lawrence; and Peter Ford from the Massachusetts Institute of
Technology , Cambridge.

organising spri

05 inches) during the survey period; about 13 percent
of the overall observed sea level rise for the same period.
Previous estimates have used various techniques, each with limitations and
uncertainties and an inherent inability to monitor the entire ice sheet mass
as a whole. Even studies that synthesized results from several techniques,
such as the assessment by the Intergovernmental Panel on Climate Change,
suffered from a lack of data in critical regions. Science data processing ,
distribution, archiving and product verification are managed jointly by JPL,
the University of Texas and GFZ.nasa.

nsf respected

When directed
toward Earth, these ejections can wreak havoc on communications ' systems from
cell phones to satellites.

arctic spri

2 millimeters (0.
Counting photons, particles that carry electromagnetic energy including X-
rays, was critical to this discovery.