Volume 8, Number 3     May/June 2000

Monitoring Winds Improves Weather Prediction

Scientists, weather forcasters and the public now have access to a valuable steam of meteorological and climate measurements and observations that could improve weather forecasting around the world. The measurements and data products show developing weather systems with unprecedented detail. NASA and the National Oceanic and Atmospheric Administration (NOAA) are working together to transition these critical measurements from research to operational missions to improve the accuracy of current weather forecasts and to extend forecast projections from three to five days.

SeaWinds was launched on June 19, 1999, and engineers and scientists have successfully calibrated the satellite and verified the accuracy of its data over the past few months. These first calibrated measurements from NASA's SeaWinds instrument on the QuikSCAT satellite became available in early February. Daily wind data and animations from the ocean-wind tracker, managed by NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, are available on the Internet at http://podaac.jpl.nasa.gov/ quikscat/, http://www-airsea.jpl.nasa.gov/seaflux and http://haifung.jpl.nasa.gov/. JPL is a division of the California Institute of Technology in Pasadena.

The measurement of wind strengths at the ocean's surface, combined with satellite measurements of clouds, temperature and other data, can be used for understanding how different weather systems and storms develop, as well as for predicting weather over the entire globe. The measurements also are crucial for understanding ocean currents, climate patterns and the cyclical and anomalous variations that occur in those patterns to help in all human situations affected by weather, according to Dr. Michael Freilich, principal investigator on SeaWinds and a professor at Oregon State University in Corvallis.

The heart of SeaWinds is a specially designed spaceborne radar instrument called a scatterometer. The radar operates at a microwave frequency that penetrates clouds. This, coupled with the satellite's polar orbit, makes the wind systems over the entire world's oceans visible to SeaWinds on a daily basis. The measurements provide detailed information about ocean winds, waves, currents, polar ice features and other phenomena for the benefit of meteorologists, climatologists, oceanographers and mariners.

"Near-real-time wind-vector measurements from SeaWinds represent a vast improvement in coverage over the generally data-sparse oceans," said SeaWinds science team member Dr. Paul Change of NOAA's National Environmental Satellite Data and Information Service. "SeaWinds data will be used operationally by marine forecasters and for numerical weather prediction models. These data promise to yield significant improvements in short-term warnings and forecasts and in medium-to long-range forecasts."

JPL manages the orbiting SeaWinds radar instrument and is providing ground science-processing systems, as well as overseeing the development of the SeaWinds radar instrument. NASA's Goddard Space Flight Center in Greenbelt, Maryland, managed the satellite's development; the satellite itself was designed and built by Ball Aerospace & Technologies Corporation in Boulder, Colorado. NOAA contributes ground system processing and distributes near-real-time SeaWinds data to the international operational weather forecasting community.

Artist's rendering of NASA's Quick Scatterometer (QuickSCAT) satellite. The large, dish-like feature at the bottom of the satellite is the scatterometer instrument that will measure winds over ocean, land and ice in a continuous, 1,800-kilometer-wide band, making approximately 400,000 measurements per day.

For more information, contact Dr. Timothy Liu at the Jet Propulsion Laboratory. 818/354-2394, liu@pacific.jpl.nasa.gov Or visit http://www.earth.nasa.gov Please mention you read about it in Innovation