Can we Create Global Precipitation Products on Demand?

The Global Precipitation Measurement (GPM) mission was launched in February 2014 as a joint mission between JAXA from Japan and NASA from the United States. GPM carries a state of the art dual-frequency precipitation radar and a multi-channel passive microwave radiometer that acts not only to enhance the radar’s retrieval capability, but also as a reference for a constellation of existing satellites carrying passive microwave sensors. These constellation products are designed for global applications, and often get merged with IR data to increase sampling to the order of 30 min. and 10 km grids. The merged products are generally adjusted for climatological biases against well established rain gauge networks. Rain gauges themselves are rarely incorporated directly because quality control can take significant time while radars are not commonly used because their quality is often unknown in a global network. There is thus little room to adapt the algorithm for specific areas that may have a different data flow, or applications that have different needs than those envisioned by the algorithm’s creator. An alternative architecture is being developed where individual data sources are pre-processed and archived – but algorithms are not created until users specify their exact needs for latency, resolution, as well as spatial and temporal consistency. While not in real time, the concept is being developed through individual applications. These will be discussed, along with progress towards the ultimate goals of creating “Products on Demand”