Global Precipitation Measurement

Global Precipitation Measurement. It is a joint satellite mission led by NASA and the Japan Aerospace Exploration Agency designed to provide next-generation observations of global rain and snow. The core observatory serves as a reference standard to unify measurements from a constellation of international partner satellites, creating a comprehensive dataset for scientific research and societal benefit. This initiative advances the understanding of Earth's water and energy cycles, improves forecasting of extreme weather events, and enhances climate models.

Mission and objectives

The primary mission is to provide frequent, high-quality global precipitation observations as a successor to the highly successful Tropical Rainfall Measuring Mission. A key objective is to calibrate measurements from an international satellite constellation using a core observatory equipped with advanced radar and radiometer instruments. This unified approach aims to produce accurate, consistent datasets for studying climate processes, freshwater resources, and weather prediction. The data supports critical applications in natural disaster monitoring, agriculture, and water resource management worldwide.

Satellite constellation and instruments

The centerpiece is the GPM Core Observatory, which carries the Dual-frequency Precipitation Radar developed by JAXA and the GPM Microwave Imager built by Ball Aerospace for NASA. This observatory flies in a non-sun-synchronous orbit to sample different times of day. The broader constellation includes satellites from partner agencies like the Indian Space Research Organisation, the Centre National d'Études Spatiales, and the European Organisation for the Exploitation of Meteorological Satellites. These partner satellites, such as those in the Global Change Observation Mission and the Meteorological Operational satellite programme, contribute complementary microwave measurements to achieve near-global coverage every three hours.

Data products and applications

The system produces a suite of data products, with the flagship Integrated Multi-satellite Retrievals for GPM algorithm combining information from all constellation sensors. These products range from fine-scale half-hourly rainfall rate maps to longer-term climate data records. The data is used operationally by agencies like the National Oceanic and Atmospheric Administration and the European Centre for Medium-Range Weather Forecasts to improve hurricane track forecasting and flood warnings. Applications extend to monitoring drought conditions for the Famine Early Warning Systems Network, managing reservoir levels by the United States Army Corps of Engineers, and validating numerical models at institutions like the Met Office.

Scientific and societal impact

Scientifically, the measurements have revised understanding of precipitation structure in cyclones and the Madden–Julian oscillation, contributing to studies published in journals like *Science* and *Nature*. The data has been instrumental in landmark climate assessments by the Intergovernmental Panel on Climate Change. Societally, near-real-time data feeds into disaster response during events like Hurricane Harvey, Typhoon Hagibis, and monsoon floods across South Asia. The long-term record also aids in analyzing trends in extreme weather and their links to phenomena like El Niño–Southern Oscillation.

International collaboration and partners

This mission is a cornerstone of international cooperation in Earth science. NASA and JAXA lead the core observatory, while the constellation and ground validation involve a broad partnership. Key contributors include the Indian Space Research Organisation with the INSAT-3D satellite, the French space agency with the Megha-Tropiques mission, and the European Space Agency through the MetOp satellites. Ground validation campaigns utilize resources from organizations like the Deutscher Wetterdienst and the Korean Meteorological Administration. Data is disseminated globally via systems like the NASA Earth Science Data Systems and serves researchers from World Meteorological Organization member states.

Category:NASA programs Category:JAXA satellites Category:Earth observation satellites