Assessment of Radio Occultation Observations with a Simplified Observing System Simulation Experiment Configuration

Soundings of refractivity or bending angle have been used worldwide in operational global models since the launch of the Constellation for Observing System for Meteorology, Ionosphere, and Climate (COSMIC) constellation in 2006. However, COSMIC is already past the end of its nominal lifetime, which has motivated the COSMIC-2 mission, a 12-satellite constellation, to be deployed in two launches. The first six satellites are planned to be deployed in March 2017 in a low-inclination orbit for dense equatorial coverage.  The second six will be deployed later in a high inclination orbit and will provide global coverage. In order to evaluate the potential impact of the COSMIC-2 observations, we have conducted a series of preliminary and simplified Observing System Simulation Experiments (OSSEs). Both equatorial (COSMIC2-A, first launch) and global (COSMIC2-B, second launch) components of the COSMIC-2 mission are considered in order to quantify the impacts of data coverage and data density. Furthermore, the potential value gained with higher number of radio occultation soundings is addressed by investigating the sensitivity of our results to several time windows in the data assimilation system.  During this talk, results from these simplified OSSEs will be discussed.