QuikSCAT

Why is Scatterometry Important?
Winds over the ocean modulate air-sea changes in heat, moisture, gases and particulates (matter in the form of small liquid or solid particles), regulating the crucial bond between atmosphere and ocean that establishes and maintains global and regional weather and climate. Data derived from ocean scatterometers is vital to researchers in their studies of air-sea interaction, ocean circulation, and their effects on weather patterns and global climate. In the past, weather data could be acquired over land, but our only knowledge of surface winds over oceans came from infrequent, and sometimes inaccurate, reports from ships and buoys. These data are also useful in the study of unusual weather phenomena such as El Niño, the long-term effects of deforestation on our rain forests, and changes in the sea ice masses around the polar regions. These environmental changes all play a central role in regulating global climate.

Winds Over the Ocean
Wind affects the full range of oceanic motion—from individual surface waves to complete current systems. The tropical Pacific Ocean and overlying atmosphere react to and influence each other. Easterly surface winds along the equator control the amount and temperature of the water that upwells (moves or flows upward) to the surface. This upwelling of cold water determines sea surface temperature distribution, which affects rainfall distribution. This in turn determines the strength of the easterly winds—a continuous cycle.

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Scatterometry
QuikSCAT
History of Scatterometry
Why is Scatterometry Important?
Applications

 
Animations

Pacific Surface Winds - This animation shows ocean surface wind speeds and directions over the Pacific as measured by the NSCAT scatterometer on September 20, 1996. Here, wind speed is depicted by the color of the ocean background: blue for low winds, red for moderate winds, and yellow for high winds. The movement of the white arrows shows the direction of the wind at about 00:00 GMT. The underlying wind field was constructed from eight orbits of NSCAT data by using a successive correction interpolation scheme. Noteworthy features manifested in this scene include: Typhoons Violet and Tom in the Northwestern Pacific near Japan, the trade winds and inter-tropical convergence zone near the equator, and strong winter storm activity in the Southern Hemisphere.

Typhoons Violet and Tom - This animation shows ocean surface wind speeds and directions in the Pacific ocean near Japan as measured by the NSCAT scatterometer on September 20, 1996. Here, wind speed is depicted by the color of the ocean background: blue for low winds, red for moderate winds, and yellow for high winds. The movement of the white arrows shows the direction of the wind at about 02:00 GMT. The underlying wind field was contructed from four orbits of NSCAT data by using a successive correction interpolation scheme. Typoon Tom is in the upper right hand corner while Typhoon Violet is just south of Japan. Typhoon Violet eventually struck the east coast of Japan causing damage and deaths.

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Pacific surface winds
QuickTime movie of Pacific surface winds (1.4MB)
Courtesy of JPL

Typhoons Violet and Tom
QuickTime movie of Typhoons Violet and Tom (1.3MB)
Courtesy of JPL

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