Simulation and Evaluation of Next Generation Microwave Satellite Observation System for Numerical Weather Prediction Applications

Satellite observations are critical for making accurate global weather forecasts, and in particular passive microwave temperature and humidity sounders have among the largest impacts. The Advanced Technology Microwave Sounder (ATMS), which currently flies on the Suomi NPP, NOAA-20 and NOAA-21 and follow-on satellite missions, provides information about the physical properties of our atmosphere, such as temperature and moisture, which heavily influence weather patterns.

This study is aimed at investigating the expected impact in NWP from future evolutions of the constellation of NOAA's operational weather satellites. It contributes to designing a cost-effective optimal US contribution to the global observing system, driven by user needs. The study will use the global forecasting system of the European Centre for Medium-range Weather Forecasts (ECMWF) to estimate the expected statistical improvement in weather forecasts resulting from new orbital and sensor capabilities. Initially, we will investigate the impact of the QuickSounder, an ATMS instrument to be launched into an early-morning orbit, thus complementing the afternoon and mid-morning orbits presently covered by the US and Europe. Next, we will evaluate the benefit of new capabilities of a future ATMS-follow-on mission, including the impact of measuring radiation at frequencies not previously covered by heritage instruments. Unlike traditional Observing System Simulation Studies, the present project will use the Ensemble of Data Assimilations method to estimate the expected impact of the new observations on short-range forecasts. Here, simulated new observations are added to a baseline of existing observations, and the reduction of the ensemble spread quantifies the expected improvement. As an international collaboration effort between ECMWF and the Cooperative Institute for Satellite Earth System Studies at the University of Maryland (UMD/CISESS), an overview of this project will be presented in this meeting.