Observation system simulation experiments for a global wind observing sounder

Abstract

Observing System Simulation Experiments (OSSEs) are a powerful tool used to assess the potential impact on numerical weather prediction skill of planned or hypothetical future observing systems. Over the past several years an international Joint OSSE collaboration has emerged centered on the use of NASA's and NOAA's data assimilation systems. A Nature Run provided by the European Centre for Medium Range Weather Forecasts (ECMWF) has undergone extensive validation, and a set of simulated reference observations have been subjected to a set of calibration experiments. One of the first candidate observing systems assessed by this system is a wind lidar based on the Global Wind Observing Sounder (GWOS) concept developed by NASA in response to the National Research Council (NRC) Decadal Survey. A set of 45‐day assimilation and forecast experiments has been set up and executed. The experiments were done using the NCEP operational forecast system, and the results show that wind lidar observations are likely to provide a significant increase in forecast skill even when used in a modern, radiance‐based assimilation system.