GNSS-RO data assimilation advancement and implementation at JCSDA and NCEP

Global Navigation Satellite Systems Radio Occultation (GNSS-RO) measurements have been assimilated into operational Numerical Weather Prediction (NWP) for more than a decade. The Joint Center for Satellite Data Assimilation (JCSDA) has been working with operational centers, including the National Centers for Environmental Prediction (NCEP), to advance GNSS-RO assimilation since the first Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) mission was launched in 2006. Lately, the follow-up mission, COSMIC-2, was launched in late June, 2019 and provides a great opportunity to review and further improve the use of GNSS-RO in operations. Besides, there are also other new GNSS-RO missions, including those international missions (e.g., METOP-C) and commercial satellites, continue to be available for evaluation and, if feasible, operational implementation.

The JCSDA is working with NCEP to take advantage of these new GNSS-RO observations and improve their usage in NWP operations. Currently, the JCSDA is developing the GNSS-RO data assimilation capability in the framework of the Joint Effort for Data assimilation Integration (JEDI). The JCSDA is also working with NCEP to test and evaluate latest RO missions, including COSMIC-2 and other missions. This paper will report the progress of these efforts.