NASA scientists using weather forecast models with newly incorporated data from the wind-measuring NASA Scatterometer (NSCAT) instrument onboard Japan's Advanced Earth Observing Satellite (ADEOS) are seeing significant improvements in their ability to analyze weather patterns and generate more accurate forecasts, especially in the Southern Hemisphere.
"Initial experiments with the wind measurements taken by the scatterometer indicate the potential to extend the useful range of weather forecasts in the Southern Hemisphere by about 24 hours," said Dr. Robert Atlas, an NSCAT science team member from NASAs Goddard Space Flight Center, Greenbelt, MD. "We have also seen improvement in early analyses and forecasts of storms in the Northern Hemisphere. Specifically, NSCAT appears to more accurately locate both cyclones and fronts, and to improve the forecasts of their location by as much as several hundred kilometers."
Such information should assist meteorologists at the National Oceanographic and Atmospheric Administrations Marine Prediction Center, Camp Springs, MD, to issue more accurate warnings that could help reduce the loss of life and property at sea and along the U.S. coastline.
Accurate measurements of wind velocity in the Southern Hemisphere have
been virtually non-existent due to the vastness of the southern ocean. The scatterometer takes 190,000 wind measurements per day, mapping more than 90 percent of the world's ice-free oceans every two days. The instrument is giving scientists more than 100 times the amount of ocean wind information that is available from ship reports or buoys. Because the scatterometer is a radar instrument, it operates 24 hours a day, collecting data day or night, regardless of sunlight or weather conditions.
"Since the August launch, weve set a new standard in terms of how quickly we have been able to calibrate and validate our instrument and get the data into the hands of the people who are using it," said Jim Graf, NSCAT project manager at NASAs Jet Propulsion Laboratory.
"Weather forecasters will be able to use these data to better predict the evolution of fronts and storms over the oceans and track them as they approach land and major population centers. The maritime industry will benefit by steering ships away from storms and towards areas with favorable tailwinds," Graf said. "By combining the scatterometer wind data with ocean height data from the TOPEX/Poseidon mission, Earth scientists are getting a first hand look at the forcing function, the winds, and the ocean's response, ocean height and waves, or the yin and yang that control much of our planet's weather and climate change."
The NSCAT project is also making the wind images available to the public via the Internet at the following address: http://www.jpl.nasa.gov/winds.
"Each day, we provide a daily wind movie of the Pacific Ocean that allows people to see the last 26 hours of NSCAT wind data. Anyone who has an interest in what the winds are doing weather forecasters, scientists, boaters, surfers, fishermen can log on and get an up-to-date picture from NSCAT," Graf said. Data of the Atlantic Ocean and other oceans will be on-line in a few weeks.
The scatterometer uses an array of stick-like antennas that radiate microwave pulses in the Ku-band across broad regions of the Earths surface. A small fraction of the energy in the radar pulses is reflected back and captured by NSCATs antennas. At any given time NSCATs array of six dual-beam antennas scans two swaths of ocean -- one on either side of the satellites near-polar, sun-synchronous 800-kilometer (500-mile) orbit. Each swath is 600 kilometers (375 miles) wide. The swaths are separated by a gap of about 350 kilometers (215 miles) directly below the satellite where no data collection is possible.
The NSCAT instrument was launched August 16, 1996 on Japan's Advanced Earth Observing Satellite (ADEOS). ADEOS is an international global change research mission of the National Space Development Agency of Japan (NASDA), which includes instruments from the United States, Japan and France, with investigators from many other countries. The satellite is a key part of an international environmental research effort that includes NASA's Mission to Planet Earth (MTPE) program, a long-term, coordinated research effort to study the Earth as a global environmental system. The goal of MTPE is to develop a better scientific understanding of natural environmental changes and to distinguish between natural and human-made changes and impacts.
The Jet Propulsion Laboratory developed, built and manages the NSCAT instrument for NASA's Office of Mission to Planet Earth, Washington, D.C.
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