Assimilation of polar orbiting satellite data in the JMA operational NWP systems

The Japan Meteorological Agency (JMA) uses various satellite data in its operational data assimilation systems (DASs) for numerical weather prediction (NWP). The data include radiances and retrievals from ATOVS onboard NOAA and Aqua satellites, and microwave radiometers (MWRs) onboard TRMM, Aqua and DMSP satellites, ocean surface wind vectors from microwave scatterometer on QuikSCAT, vertical refractivity profiles from Global Positioning System- Radio Occultation (GPS-RO), atmospheric motion vectors (AMV) from imagers onboard Aqua, Terra and geostationary satellites, and clear sky radiances from MTSAT-1R imager. They are all inevitable to keep and improve the accuracy of NWP, and we continue to improve the usage and introduce new satellite data. This paper describes the current usage of data from polar orbiting satellites and their impacts on analyses and forecasts mainly in the global DAS