Preliminary evaluation of the COSMIC-2 GNSS Radio Occultation Data using multiple forward operators in JEDI UFO

Multiple Global Navigation Satellite System (GNSS) Radio Occultation (RO) observation operators have been under development and test in the Unified Forward Operator (UFO) of the Joint Effort for Data assimilation Integration (JEDI) framework. Operators including those used in the operations of NCEP, ECMWF, and US navy are adapted in JEDI. These RO operators are featured by a number of configurable parameters that can be specified in a runtime yaml file. These configurable parameters are implemented in common modules that are independent of operators. Therefore, we can separate concerns and tackle the fundamental issues and challenges in RO assimilation such as the potential impact of the deep-tracked RO soundings, the super refraction quality control, the observation errors, etc. In addition, we can also compare directly the performance of multiple operators using the exactly same background and observation in the same framework.

This work will demonstrate how the JEDI RO operators can facilitate the research-to-operation (R2O) transition of the newly available RO data (data is expected to be available to JCSDA in August) from the FORMOSAT-7/COSMIC-2 (COSMIC-2) RO mission which was launched in June 2019 and promises to improve weather and space weather prediction. We will present the impact of COSMIC-2 data in a quasi-operational system in comparison with other RO data that are already in operations. We will also evaluate the impact of various RO operators and configurations.