Jun 20, 1999

El Nino Watcher Blasts Off





NASA's QuickScat ocean winds satellite successfully launched




NSCAT measures ocean winds
June 20, 1999: NASA's Quick Scatterometer (QuikScat) was lofted into space at 7:15 p.m. Pacific Daylight Time yesterday atop a U.S. Air Force Titan II rocket from the Vandenberg Air Force Base in California. The satellite was launched in a south-southwesterly direction, soaring over the Pacific Ocean at sunset as it ascended into Earth orbit. [More launch details]

Right: QuickScat's predecessor, NSCAT, a microwave radar scatterometer, measured near-surface wind vectors (both speed and direction) over the global oceans starting in August 1996. The SeaWinds on QuikSCAT mission is a "quick recovery" mission to fill the gap created by the loss of data from the NASA Scatterometer (NSCAT), when the satellite it was flying on lost power in June 1997. [More information] Photo Credit: JPL


Built in record time in just 12 months, QuikScat will provide climatologists, meteorologists and oceanographers with daily, detailed snapshots of ocean winds as they swirl above the world's oceans. This satellite will be NASA's next "El Niño watcher." It will be used to better understand global weather abnormalities and to generally improve weather forecasting.

Winds play a major role in every aspect of weather on Earth. They directly affect the turbulent exchanges of heat, moisture and greenhouse gases between Earth's atmosphere and the ocean. To better understand their impact on oceans and improve weather forecasting, the satellite carries a state-of-the-art radar instrument called a scatterometer for a two-year science mission.


Recent Headlines
December 3: Mars Polar Lander nears touchdown

December 2: What next, Leonids?

November 30: Polar Lander Mission Overview

November 30: Learning how to make a clean sweep in space
"Knowledge about which way the wind blows and how hard is it blowing may seem simple, but this kind of information is actually a critical tool in improved weather forecasting, early storm detection and identifying subtle changes in global climate," said Dr. Ghassem Asrar, associate administrator of NASA's Office of Earth Science, Washington, DC.

The mission will help Earth scientists determine the location, structure and strength of severe marine storms - hurricanes in the Atlantic, typhoons near Asia and mid-latitude cyclones worldwide - which are among the most destructive of all natural phenomena. The National Oceanic and Atmospheric Administration (NOAA), a chief partner in the QuikScat mission, will use mission data for improved weather forecasting and storm warning, helping forecasters to more accurately determine the paths and intensities of tropical storms and hurricanes.
As NASA's next "El Niño watcher," QuikScat will be used to better understand global El Niño and La Niña weather abnormalities. Changes in the winds over the equatorial Pacific Ocean are a key component of the El Niño/La Niña phenomenon. QuikScat will be able to track changes in the trade winds along the equator.

Left: TOPEX/Poseidon's sea-surface height measurements have provided scientists with a detailed view of the 1998-99 La Niña and the 1997-98 El Niño because the satellite's altimeter measures the changing sea-surface height with unprecedented precision. In this image, which shows the lingering effects of La Nina in May 1999, the purple areas are about 18 centimeters (7 inches) below normal, creating a deficit in the heat supply to the surface waters. The white areas show the sea surface is between 14 and 32 centimeters (6 to 13 inches) above normal; in the red areas, it's about 10 centimeters (4 inches) above normal. Changes in the winds over the equatorial Pacific Ocean are a key component of the El Niño/La Niña phenomenon. QuikScat will be able to track changes in the trade winds along the equator and, thus, complement data from NASA's other Earth-watching satellites. Photo Credit: JPL

Scatterometers operate by transmitting high-frequency microwave pulses to the ocean surface and measuring the "backscattered" or echoed radar pulses bounced back to the satellite. The instrument senses ripples caused by winds near the ocean's surface, from which scientists can compute the winds' speed and direction. The instruments can acquire hundreds of times more observations of surface wind velocity each day than can ships and buoys, and are the only remote-sensing systems able to provide continuous, accurate and high-resolution measurements of both wind speeds and direction regardless of weather conditions.

The satellite is the first obtained under NASA's Indefinite Delivery/Indefinite Quantity program for rapid delivery of satellite core systems. The procurement method provides NASA with a faster, better and cheaper method for the purchase of satellite systems through a "catalog," allowing for shorter turnaround time from mission conception to launch. Total mission cost for QuikScat is $93 million.



subscription image.

Sign up for our EXPRESS SCIENCE NEWS delivery
Fifteen times a day, the satellite will beam down collected science data to NASA ground stations, which will relay them to scientists and weather forecasters. SeaWinds will provide ocean wind coverage to an international team of climate specialists, oceanographers and meteorologists interested in discovering the secrets of climate patterns and improving the speed with which emergency preparedness agencies can respond to fast-moving weather fronts, floods, hurricanes, tsunamis and other natural disasters.

By combining QuikScat's wind data with information on ocean height from another ocean-observing satellite, the joint NASA- French TOPEX/Poseidon mission, scientists will be able to obtain a more complete, near-real-time look at wind patterns and their effects on ocean waves and currents, said Dr. Timothy Liu, QuikScat project scientist at NASA's Jet Propulsion Laboratory, Pasadena, CA. He added that QuikScat will complement data being collected by other Earth-monitoring satellites such as NASA's currently orbiting Tropical Rain Measurement Mission (TRMM) and Terra, which will be launched later this year.


Web Links 

Ocean observing satellite set to chase the wind -- JPL press release

QuickScat ocean wind satellite successfully launched -- JPL press release

More Space Science Headlines - NASA research on the web

NASA's Office of Space Science press releases and other news related to NASA and astrophysics


Join our list of subscribers, 60,000 and growing!! - sign up for our express news delivery and you will receive a mail message every time we post a new story!!!




return to Space Science News Home

For more information, please contact:
Dr. John M. Horack , Director of Science Communications
Source: NASA Press Release
Editor: Dr. Tony Phillips
Curator: Bryan Walls
NASA Official: John M. Horack