Evaluation of the Impact from CrIS Full Spectral Resolution, ABI, and Other Satellite Radiance Data on the RAP Hourly Updated Assimilation System

Version 4 of the Rapid Refresh (RAP) was implemented operationally at the National Centers for Environmental Prediction (NCEP) in July 2018. This implementation included a significant radiance upgrade package with greater use of direct broadcast/readout data as well as assimilation of data from new sensors (e.g., ATMS and CrIS from S-NPP etc.). The RAP analysis uses the Gridpoint Statistical Interpolation (GSI) hybrid variational/Ensemble Kalman Filter (EnKF) data assimilation system including an advanced satellite radiance assimilation package developed at NCEP, with ensemble information for the regional assimilation application obtained from the 80-member global ensemble data assimilation system.

We are currently testing a number of satellite radiance enhancements for the next RAP operational upgrade (RAP version 5 planned for 2020). These enhancements include the assimilation of GOES-16 ABI infrared radiance data, CrIS Full-Spectral-Resolution (FSR) data both from S-NPP and NOAA-20, and ATMS data from NOAA-20. As part of the development for this upgrade, we are evaluating a variety of issues associated with the assimilation of these new and expanded data sets. These issues include channel selection, quality control, and bias correction, as well as an examination of data coverage. A series of RAP retrospective runs are being conducted to evaluate the forecast impact from these new instruments/data separately and/or combined together. At the conference, we will report on this work and provide an update on other aspects of the RAP satellite data assimilation upgrade package.