Advances and Outlook for International Mainstream Multi-Source Precipitation Merging Products

Precise, accurate and highly efficient grid precipitation real-time products are of great significance for intelligent grid forecasting, disaster prevention and reduction, water cycle and land-atmosphere interaction. Since the 1990s, the United States, Japan and the European Union have successively started to develop precipitation fusion products using ground observation, satellite, radar, model and other multi-source data and formed a series of regional or global multi-source fusion precipitation realtime products. At present, among the global precipitation real-time products, the Integrated Multi-Satellite Retrievals for GPM (IMERG) product developed by NASA of the United States has launched the sixth generation, expanding the data coverage to the whole world, combining the geosynchronous infrared data, microwave data, ground rain gauge data, etc., and forming a precipitation fusion product with high spatial and temporal resolution. The GSMaP product launched by Japan adopted PMW (Passive Microwave) algorithm, snow estimation algorithm and other methods, and developed high quality precipitation products. In terms of regional high-resolution precipitation real-time products, the radar QPE (Quantitative precision estimation) product developed by the latest operational MRMS (Multi Radar/Multi Sensor System) of the United States has generated 1km, 2 min updated precipitation products in the United States based on radar raw data, ground rain gauge data, model data, etc.. The research on multi-source precipitation fusion technology in China started relatively late and has been gradually carried out since 2010. In 2018, the National Meteorological Information Center took the lead, and the real-time precipitation fusion product of hourly and 5 km resolution, which integrated ground-based data, satellite data and radar data, was applied in the operational forecast . As a real-time product, it has been used in China’s seamless smart grid forecasting operation. And the spatial resolution of the product was increased to 1km in 2021. However, it is necessary to realize that there is still a gap between Chinese real-time precipitation products and the demand for disaster weather monitoring and warning, high-frequency rolling update of intelligent forecasting and smart meteorological services. The gap also exists between our products and the most advanced technology in international precipitation real-time product development. Our global precipitation products are still heavily dependent on international products. Hence it is of great significance to follow the latest development of technologies in international multisource integrated precipitation products and carry out research targeting for the core technologies of precipitation fusion products so as to improve the quality of precipitation real-time products in China.