Precipitation Processing System (PPS) servers will be down for extended maintenance from Tuesday, September 22nd through Thursday September 24th. During this time the PPS websites, the PMM Publisher API, and the GPM research data server (arthurhou) will be unavailable. The GPM near real-time server (jsimpson) and satellite data collection will not be affected. Click here to learn more.

PMM

Content which is not specifically affiliated with GPM or TRMM, but which is about the Precipitation Measurement Missions in general.

Diagram of raindrop shape
High in the atmosphere, water collects on dust and smoke particles in clouds. Raindrops start to form in a roughly spherical structure due to the surface tension of water. This surface tension is the "skin" of a body of water that makes the molecules stick together. The cause is the weak hydrogen bonds that occur between water molecules. On smaller raindrops, the surface tension is stronger than in larger drops. The reason is the flow of air around the drop. As the raindrop falls, it lose that rounded shape. The raindrop becomes more like the top half of a hamburger bun. Flattened on the...
GPM flying over Earth with a data swath visualized.
Problem-Based Classroom Modules A series of PDF files which provide full classroom lessons and problem sets for a number of precipitation-related topics. The Shape of a Raindrop A lesson on what causes raindrops in our atmosphere to be a certain shape. Create a Sphere with Precipitation Climatology Click above to download the PDF file. This is an activity in which students will cut and fold paper to create a 3D sphere which displays the precipitation climatology (long-term average) computed by the Global Energy and Water Experiment for 1979-2008. This activity was created by Dr. Chris Kidd and...
GPM flying over Earth with a data swath visualized.
Malaria outbreaks after the 2010 floods in Pakistan, E. coli and colliform from raw sewage in Mississippi flood waters, and cholera spread by heavy rains in Cameroon, West Africa are among the many health hazards associated with flood disasters and torrential rains. In developing regions with limited clean water infrastructure and health resources that are stretched thin, any advanced warning can make a huge difference in the health community’s response to help people in need. Flooding in Gonaives Haiti before and after the 2004 tropical storm Jeanne Using satellite data to forecast disease...