The Tropical Rainfall Measuring Mission (TRMM) is presented. TRMM is a satellite program being studied jointly by the United States and Japan which would carry out the systematic study of tropical rainfall required for major strides in weather and climate research. The scientific justification for TRMM is discussed. The implementation process for the scientific community, NASA management, and the other decision-makers and advisory personnel who are expected to evaluate the priority of the project is outlined. Simpson, Joanne (Editor) Goddard Space Flight Center CLIMATOLOGY; DATA ACQUISITION; METEOROLOGICAL SATELLITES; RAIN; TROPICAL METEOROLOGY; INTERNATIONAL COOPERATION; JAPAN; METEOROLOGICAL PARAMETERS; REMOTE SENSING...

"The Tropical Rainfall Measuring Mission (TRMM), a satellite program now being studied jointly by the United States and Japan, would carry out the systematic study of tropical rainfall required for major strides in weather and climate research ... This report presents the scientific justification for TRMM and outlines the implementation process for the scientific community."--Preface.

Launched jointly in 1997 by the National Aeronautics and Space Administration (NASA) and the Japan Aerospace Exploration Agency (JAXA), the Tropical Rainfall Measuring Mission (TRMM) is a satellite mission that placed a unique suite of instruments, including the first precipitation radar, in space. These instruments are used to monitor and predict tropical cyclone tracks and intensity, estimate rainfall, and monitor climate variability (precipitation and sea surface temperature). TRMM has been collecting data for seven years; this data is used by the Joint Typhoon Warning Center, the National Center for Environmental Prediction, and the National Hurricane Center, among others worldwide. In July 2004, NASA announced that it would terminate TRMM in August 2004. At the request of the National Oceanic and Atmospheric Administration (NOAA), the White House, and the science community, NASA agreed to continue TRMM operations through the end of 2004. Meanwhile, NASA asked a National Research Council (NRC) committee to provide advice on the benefits of keeping TRMM in operation beyond 2004. After holding a workshop with a number of experts in the field, the committee found that TRMM will contribute significantly to operations and science if the mission is extended; and therefore, strongly recommends continued operation of TRMM with the caveat that cost and risk will need to be further examined before a final decision about the future of TRMM can be made.