January 29, 2004
NASA Satellites See Ocean Conditions in 3-D, Improve Forecasts
Freighters, cruise lines, marine rescuers and coastal managers are among
those who could benefit from prototype three-dimensional, three-day ocean
condition forecasts created with the assistance of NASA satellite data,
computer models and on-site ocean measurements.
Scientists hope to forecast ocean conditions several days ahead, much
like regional weather forecasts broadcast on television news. “It’s
a three-dimensional look at the ocean, from the surface to the ocean
bottom,” said Yi Chao of NASA’s Jet Propulsion Laboratory
(JPL), Pasadena, Calif., lead scientist on the project. Chao and three
colleagues presented their real-time operational forecast system for
the Central California Ocean at the recent Annual Meeting of the American
Meteorological Society (AMS).
The end product from our 3-D ocean model includes temperature, salinity
and current,” Chao said. These are available as text or binary
data, or can be visualized for further analysis. Seeing the ocean in
three dimensions, and knowing how it will behave from top to bottom,
will save fuel costs for large shippers by steering away from choppy
waters, or moving with the current. The data will also help Coast Guard
rescuers, as they would be able to determine which direction people stranded
in the water would drift. Several satellite measurements provide input
into the forecast system, including near-real time wind data from the
Quikscat instrument on NASA’s SeaWinds satellite; ocean height,
including waves, measured from NASA’s Topex/Poseidon and Jason
satellites; sea surface temperatures measured by the National Oceanic
and Atmospheric Administration’s (NOAA) Polar Orbiting Environmental
Satellites (POES) Advanced Very High Resolution Radiometer instrument.
Aircraft data from the Office of Naval Research is used on cloudy days,
when satellites cannot see the ocean surface. A variety of sensors, such
as sea gliders that can dive from the ocean surface to several hundred
meters depth, ships, and autonomous underwater vehicles, provide ocean
water temperature and salinity data. Meters measure ocean currents, and
shore-based high-frequency radars provide ocean surface current data.
Once these data were input into the forecast system, existing ocean conditions
were simulated in 3-D, within 24 hours behind real-time, and more accurate
three-day forecasts were then generated in 3-D.
Chao said the NASA 3-D ocean models were useful in planning daily ocean
measurement missions during a field campaign conducted last summer in
Monterey Bay, Calif. Mission scientists used the forecasts to find interesting
areas to observe, such as where cold water from the ocean bottom came
up to the surface. Wherever the models seemed to generate an error, more
observations were planned, so the forecasts could be improved.
Data are only available for Monterey Bay, where the prototype system
was first tested. The next test site will stretch along the coast from
San Diego to Baja, Calif. System data are not yet available for public
use. Sixteen institutions are evaluating the system or providing data.
The researchers hope to eventually issue round-the-clock operational
forecasts along all U.S. coastal areas.
In addition to helping with ocean condition forecasts, NASA also is
interested in studying the coastal ocean to monitor resources for many
purposes including recreation, conservation and commerce. Satellites
provide the high-resolution imagery to accomplish this task.
NASA and the Office of Naval Research jointly funded this research.
The forecast system exemplifies NASA’s Earth Science Enterprise
Coastal Management national application, where agency aerospace research
and development of science and technologies are being used with other
federal agencies such as NOAA.
For information about NASA and agency programs on the Internet, visit:
http://www.nasa.gov
For more information about 3-D ocean models and images on the Internet,
visit:
http://www.gsfc.nasa.gov/topstory/2004/
0113forecastca.html
For a copy of the study abstract from the AMS meeting, visit:
http://ams.confex.com/ams/84Annual/
techprogram/paper_73425.htm
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Contacts:
Elvia H. Thompson
Headquarters, Washington
Phone: 202/358-1696
Alan Buis
Jet Propulsion Laboratory, Pasadena, Calif.
Phone: 818/354-0474
Rob Gutro
Goddard Space Flight Center, Greenbelt, Md.
Phone: 301/286-4044 |
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How Ocean Data Were Collected
Credit: Monterey Bay Aquarium Research Institute
High-resolution Image
Sea Surface Temperatures by Satellite
This is an image of Sea Surface temperature from August 15, 2003 of Monterey Bay, Calif. from the AVHRR aboard NOAA's GOES satellite. Credit: Monterey Bay Aquarium Research Institute
Wind Data from QuickSCAT
This is a QuikSCAT image of winds on the surface of the Pacific Ocean
on January 8, 2004. Credit: NASA JPL
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