The amount of water vapor in the atmosphere determines when and where clouds form. Tracking precipitation and its relationship to global climate, however, has been difficult because the data have not been recorded into coordinated databases until recently. In addition, precipitation measurements vary widely across small geographic areas making it difficult to measure accurately. Through further study, NASA and researchers at GISS hope to create more accurate models from which conclusions about global rainfall can be drawn. The TRMM mission includes the first spaceborne rain radar.
Tropical rainfall comprises more than two-thirds of global rainfall.
Data from the TRMM mission should greatly enhance researchers' understanding and prediction abilities of global climate change.