The VIIRS Cloud Product: Potential Applications and Incorporation in FV3GFS

The Visible Infrared Imaging Radiometer Suite (VIIRS) cloud product provides cloud properties (e.g. cloud type, phase, and height) at the global scale. Cloud related variables form a critical component of the National Centers for Environment Prediction’s (NCEP) Finite Volume Cubed Sphere Dynamical Core (FV3) based Global Forecast System (FV3GFS). These variables include cloud amount, cloud liquid water content, and are employed both in the quality control procedures of radiance assimilation (e.g. ATMS microwave radiance assimilation) and the radiative transfer calculations. Several of these variables are estimated in FV3GFS based on parameterizations from previous studies. In addition, the current ATMS quality control procedures in FV3GFS do not include an explicit product with cloud information which could result in significant errors in filtering radiance observations. This work focuses on the various applications of cloud variables in FV3GFS (including ATMS quality control) and the impacts of incorporating the cloud variables available from VIIRS (both at the quality control stage for ATMS and as a potential substitute for the current FV3GFS cloud variables) on FV3GFS forecasting performance.