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Suomi NPP Satellite Sees Tropical Storm Isaac at Night
satellite image of Isaac Credit: NASA
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Exceptionally crisp nighttime images of Hurricane Isaac as it made landfall this week were made possible by the Suomi National Polar-orbiting Partnership satellite (NPP).

The images of Isaac lit by moonlight at 1:57 a.m. CDT, Aug. 29, 2012, were acquired by NPP's Visible Infrared Imaging Radiometer Suite (VIIRS) "day-night band."

No other operational satellite available to forecasters can provide such clear nighttime images, says Kathy Strabala, a meteorologist and assistant scientist at the University of Wisconsin-Madison. She adds that Suomi NPP data is available right away. "Our use of the direct broadcast antenna means that we can acquire the data in real-time as the satellite overpasses our region."

Meteorologists also can use these nighttime images along with observations from other satellites such as the Tropical Rainfall Measuring Mission to help forecast the strength and direction of hurricanes. University of Wisconsin-Madison meteorology professor Scott Lindstrom says, "You get a visible image at high resolution, in the middle of the night, so you can identify some very key features."

Lindstrom says this information is useful in indicating hurricane intensification, the potential for severe weather, heavy rain and turbulence. For example, he says, this image shows a moonlit "anvil," that's the term used for the highest tops of the storm. It also shows what's called "transverse banding" at the edge of the clouds. Lindstrom says that when those details can be viewed, "a forecaster will know immediately where to expect the heaviest rain and potential for aviation turbulence."

Suomi NPP is the result of a partnership between NASA, the National Oceanic and Atmospheric Administration (NOAA) and the Department of Defense. The ground segment for Suomi NPP is provided by NOAA's Joint Polar Satellite System.

For more information about NASA satellite observations of Hurricane Isaac, visit: http://www.nasa.gov/mission_pages/hurricanes/archives/2012/h2012_Isaac.html.
Laura Betz
NASA's Goddard Space Flight Center, Greenbelt, Md.