NASA/JAXA Global Precipitation Measurement (GPM) mission has produced its first global map of rainfall and snowfall, from April to September 2014. The data map combines measurements from 12 satellites and the GPM Core Observatory, launched February 27, 2014. It covers 87 percent of the globe that falls between 60 degrees north and 60 degrees south latitude and is updated every half hour.
The map covers more of the globe than any previous NASA precipitation data set and has repeat coverage every three hours, allowing scientists to see how rain and snow storms move around nearly the entire planet. As scientists work to understand all the elements of Earth’s climate and weather systems, and how they could change in the future, GPM provides a major step forward in providing the scientific community comprehensive and consistent measurements of precipitation.
Falling rain and snow are essential parts of Earth's water cycle, which moves water and heat energy around Earth. Near the equator where the Sun's heat drives evaporation that keeps the air moist, rain systems move westward in a steady stream. At higher latitudes, which have not previously been observed in 3-D with high-resolution precipitation sensors, enormous storm fronts march eastward across North America and Europe in the Northern Hemisphere, and across the Southern Ocean that surrounds Antarctica.
For the first time with this near-global map, light rain and snow are being tracked consistently through these high latitudes and across oceans.
GPM's global precipitation maps expand upon and continue the precipitation data record collected by its predecessor, the Tropical Rainfall Measuring Mission, which was launched in 1997.
The precipitation data as well as the entire catalogue of GPM data are freely available to registered users from Goddard's Precipitation Processing System.