NASA - National Aeronautics and Space Administration

For more information contact:

Elvia H. Thompson
Headquarters, Washington
(Phone 202/358-1696)

Krishna Ramanujan
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-3026)

For information about TRMM rain and flood maps on the Internet, visit: http://trmm.gsfc.nasa.gov/

For information about NASA and Earth Science projects on the Internet, visit: http://www.nasa.gov

Caption for Image 1: Spring Flooding in the Southeast

Data from TRMM and other satellites estimated more than 16 inches of rain fell in the red areas of the top map (TN, AL, GA) from May 4-9, 2003 from spring storms. Credit: Hal Pierce/Jeff Halverson, NASA Goddard Space Flight CenterHigh Resolution for Image 1

Caption for Image 2: Southeast Flood Rainfall Statistics

Left graph shows rain fell as much as 35 mm (1.4 inches) per hour over the 5 day period. Right graph shows that after 85 hours, rain totaled 472.7 mm (18.6 inches) within a 200 km (77 mile) radius surrounding Nashville, TN.
Credit: Hal Pierce/Jeff Halverson, NASA Goddard Space Flight Center High Resolution for Image 2

Caption for Image 3: Global Flood Potential Map, May 2, 2003

Red regions on this map show areas that have received a 24-hour rainfall accumulation greater than 1.5 inches. These flood potential maps are generated for 1-day, 3-day and 7-day time periods and are available on the TRMM website. Credit: Hal Pierce, NASA Goddard Space Flight Center
High Resolution for Image 3

Caption for Image 4: Flooding in Brazil, January 21, 2003

This dramatic image captures a week's worth of torrential rainfall over a small region near Belo Horizonte, Brazil, where the death toll from mudslides has been climbing. Mudslides developed in the mountainous terrain of the Brazilian Highlands where runoff from up to sixteen inches of rain swept through hillside villages. This is more rain than Denver, Colorado or Los Angeles, California receive in an entire year. The image was created using a technique that combines data from NASA's Tropical Rainfall Measurement Mission (TRMM) with other rainfall-measuring satellites (from NASA’s Earth Observatory Website). Red regions have received over 14 inches of rainfall. Credit: Hal Pierce, NASA Goddard Space Flight Center

Caption for Image 5: Flooding in Western Australia, January 23rd to 25th, 2003

Heavy seasonal rains recently fell over a small region of Western Australia from January 23rd to the 25th. While rainfall normally occurs this time of year as part of the southern summer monsoon trough, several large, organized cloud clusters bearing heavy rains moved eastward off the Indian Ocean during a 48-72 hour period, sweeping over the same region. The portion of the country receiving the heavy rains is also mountainous (the Hamersley Range), which may have contributed to the flooding by focussing heavy downpours over small regions, and concentrating the runoff into narrow stream valleys. The image shows the isolated nature of the rain accumulation over a nine day period starting on January 20, 2003. Local area accumulations approaching twenty inches are indicated on the rainmap, which was created using data from NASA's Tropical Rainfall Measurement Mission (TRMM) satellite combined with data from other rain measuring satellites. The heavy rains followed a yearlong drought in this region, which was also ravaged by severe wildfires, and washed out roads connecting small towns (from NASA’s Earth Observatory Website). Red regions have received over 20 inches of rainfall. Credit: Hal Pierce, NASA Goddard Space Flight Center

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May 12, 2003 - (date of web publication)

	Image 1

Your local weather forecaster uses Doppler radar systems, covering U.S. regions, to estimate rainfall and flooding, but NASA research satellites can see rainfall
worldwide.

Data from NASA's Tropical Rainfall Measuring Mission (TRMM) satellite, along with information from other satellites, allows researchers to see how much rain is falling over most of the world every three hours. This capability enables scientists to daily map areas of potential flooding.

	Image 2

These maps, available to the public on the Internet, will
help water resource managers and scientists around the world by providing near-real time data of rainfall and flood potential. TRMM is considered a unique "rain gauge in the sky," because its instruments can look into clouds to determine rainfall, while other satellites can only see flooded areas after floods have occurred.

Because of its extraordinary capability, TRMM is used to calibrate and fine-tune measurements of rainfall taken by other satellites, leading to current updated records on a global scale. Once baselines are established, researchers use the higher quality TRMM data wherever possible and fill in the gaps with data from other satellites to get a more complete picture of rainfall around the world.

	Image 3

"This ability to detect potential floods is extremely useful
for disaster monitoring," said Robert Adler, TRMM Project
scientist at the Goddard Space Flight Center, Greenbelt, Md.
"The rainfall maps are also useful in assessing the state of crops in remote regions, especially in the tropics," he said.

Maps that show areas of potential floods use precipitation radar data and high-resolution measurements of water content of clouds made by microwave radiometers. The maps span the Earth from 50 degrees north latitude to 50 degrees south latitude (an area just north of the U.S.-Canadian border and south to the tip of Argentina).

	Image 4

There are three variations of the rainfall accumulation maps, including 24-hour maps showing areas where more than 35 mm (1.37 inches) of rain has accumulated; maps with three-day accumulations of more than 100 mm (3.93 inches); and maps depicting areas with weeklong accumulations of more than 200 mm (7.87 inches).

Another map product, updated every three hours, shows a global snapshot of rainfall. A seven-day "movie loop" of the images allows users to track storms as they travel over land and oceans around the globe. Researchers use these near-global rainfall maps to monitor formation and dissipation of El Nino/Southern Oscillation conditions, soil moisture, and ocean salinity. These maps also are useful to water resource managers and farmers around the world.

	Image 5

The Adler led team of NASA scientists produced these TRMM
rainfall and flood potential maps. The maps merge data from
the TRMM Microwave Imager Precipitation Radar with
information from other microwave satellites and geosynchronous weather satellite infrared data. Exploiting the strengths of multiple data sources increases the accuracy of the maps.

TRMM is a joint U.S.-Japanese mission and part of NASA's Earth Science Enterprise, a long-term research program designed to study the Earth's land, oceans, air, ice and life as a total system. The TRMM satellite was launched on November 27, 1997.

NASA's Earth Science Enterprise is dedicated to understanding the Earth as an integrated system and applying Earth System Science to improve prediction of climate, weather and natural hazards, using the unique vantage point of space.

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