NHNE News List
Current Members: 1351
Subscribe/unsubscribe/archive info at the bottom of this message.

NHNE Climate Change Reference Page:
http://www.nhne.com/climatechange/

------------

NASA GAINS INSIGHT TO EARTH'S RISING TIDES
Science Blog / NASA
July 8, 2005

http://www.scienceblog.com/cms/node/8396

For the first time, researchers have the tools and expertise to understand
the rate at which sea level is changing and the mechanisms that drive that
change.

Sea levels rise and fall as oceans warm and cool and as ice on land grows
and shrinks. Other factors that contribute to sea level change are the
amount of water stored in lakes and reservoirs and the rising and falling of
land in coastal regions.

"From the Mississippi Delta to the Maldives Islands off the coast of India
to the multitude of other low-lying coastal areas around the world, itıs
estimated that over 100 million lives are potentially impacted by a
three-foot increase in sea level," said Dr. Waleed Abdalati, head of the
Cryospheric Sciences Branch at NASAıs Goddard Space Flight Center,
Greenbelt, Md. "This is an ideal time, during the midst of an historic year
of both related natural events and research developments tied to this
critical global issue, to talk to the public about whether ice in our polar
regions is truly melting, whether our oceans are indeed rising faster, and
what these changes may mean to us."

NASA is taking advantage of its unique space-based satellite observations of
Earthıs oceans and atmosphere, in combination with satellite observations
and sea surface measurements from domestic and international partners, to
learn more about why and how the worldıs waters are rising. In doing so, the
agency is hoping to determine more about factors leading to sea level
change, indicators of change such as ocean expansion, changes in ice,
impoundment of water, and movement of Earth and coastal regions, and how the
latest research developments contribute to our knowledge of sea level rise.

NASA is working with NOAA, the National Science Foundation, and others to
explore and understand sea level change -- to tell the story of what is
happening. NASA focuses on developing ways to look at sea level change using
data from NASA satellites and aircraft instruments, as well as ground and
air observations and ocean measurements from partners.

NASA satellite missions devoted to sea level research include: the Gravity
Recovery And Climate Experiment (GRACE), which maps Earthıs gravitational
field with precision and resolution, and whose data helps us better
understand movement of water throughout the Earth; the Ocean TOPography
Experiment (TOPEX/Poseidon), a joint U.S./French satellite that uses radar
to map the precise features of the oceansı surface; Jason, which measures
ocean height and monitors ocean circulation; and the Ice, Cloud and Land
Elevation Satellite (ICESat), whose primary purpose is to study the mass of
polar ice sheets and their contributions to global sea level change.

According to Dr. Laury Miller, Chief of the NOAA Laboratory for Satellite
Altimetry in Washington, the big news that has emerged over the past few
years is that the rate of 20th Century sea level rise is about two
millimeters per year and that only a quarter of this is due to expansion
caused by warming of the oceans. This provides an important context for
these recent observations.

³Weıve found that the largest likely factor for sea level rise is changes in
the amount of ice that covers Earth. Three-fourths of the planetıs
freshwater is stored in glaciers and ice sheets, or about 220 feet of sea
level," said Dr. Eric Rignot, Principal Scientist for the Radar Science and
Engineering Section at NASAıs Jet Propulsion Laboratory in Pasadena, Calif.
Research results by Rignot and partners, published in an October 2004
article in Science Magazine, further offer evidence that ice cover is
shrinking much faster than thought, with over half of recent sea level rise
due to the melting of ice from Greenland, West Antarcticaıs Amundsen Sea,
and mountain glaciers.

The latest sea level research conducted by Dr. Steve Nerem, Associate
Professor, Colorado Center for Astrodynamics Research at the University of
Colorado in Boulder, and his colleagues, published in a 2004 issue of Marine
Geodesy Journal, has found that recent TOPEX/Poseidon and Jason satellite
observations show an average increase in global mean sea level of three
millimeters a year from 1993-2005. This rate is more than 50 percent greater
than the average rate of the last 50 years.

"Now the challenge is to develop an even deeper understanding of what is
responsible for sea level rise and to monitor for possible future changes.
That's where NASAıs satellites come in with global coverage, and ability to
examine the many factors involved," said Miller.

------------

NHNE News List:

To subscribe, send a message to:
nhnenews-subscribe@yahoogroups.com

To unsubscribe, send a message to:
nhnenews-unsubscribe@yahoogroups.com

To review current posts:
http://groups.yahoo.com/group/nhnenews/messages

Published by David Sunfellow
NewHeavenNewEarth (NHNE)
eMail: nhne@...
NHNE Website: http://www.nhne.com/
Phone: (928) 282-6120
Fax: (815) 642-0117

Appreciate what we are doing?
You can say so with a tax-deductible donation:
http://www.nhne.com/main/donations.html

P.O. Box 2242
Sedona, AZ 86339