The impact study on Configurable Reflectarray for Electronic Wideband Scanning Radiometry (CREWSR) for Hurricane Ian (2022) forecast

CREWSR is a future microwave imaging and sounding sensor that offers low-power, low-mass, low-cost, high-performance, and compatibility with ESPA-class (Evolved Expendable Launch Vehicle (EELV) Secondary Payload Adapter) small satellite systems. CREWSR will demonstrate a highly configurable SmallSat based microwave temperature sounder on several key capabilities: the spatial resolution, the sampling distance between two nearby field of views (FOVs), the ability to scan anywhere within its scene to allow angular sampling, the number of spectral channels, and the observation noise. These capabilities will optimize the observation so that more observations can be made in regions that are data sensitive. This work focuses on evaluating three configurable aspects of CREWSR: the spatial resolution, the sampling distance, and the angular samplings.

A quick regional hybrid Observing System Simulation Experiment (OSSE) work was conducted to understand the added-value of CREWSR on Hurricane Ian (2022) forecast. The hybrid OSSE is based on GSI/WRF system with real observations for all existing observations. The future sensors are simulated from ERA5. Four assimilation experiments were carried out: (1) the control (CNTRL) assimilates most of the existing measurements using real observations, including GTS, most of the microwave and IR sounders, (2) Experiment 1 (EXP1) assimilates everything from CNTRL plus the ATMS data in an early morning orbit (also simulated from ERA5), (3) Experiment 2 (EXP2) assimilates everything from CNTRL plus the CREWSR data in an early morning orbit thinned with 60 km, and (4) Experiment 3 (EXP3) assimilates everything from CNTRL plus the CREWSR data in an early morning orbit thinned with 30 km. Based on the experiments, the results showed that the assimilation of both CREWSR and ATMS radiances in the early morning orbit helps improve the Hurricane Ian (2022) forecast, CREWSR radiances further improve the forecast over the ATMS data, and the assimilation of CREWSR radiances with the thinning box of 30 km instead of 60 km further enhances the forecast. These results emphasize the potential benefits of filling the data gap left by JPSS and Metop series. More importantly, a microwave sounder like CREWSR, with the capability to provide more observations in data sensitive region and fewer observations in data insensitive region, has the potential to further improve hurricane forecast beyond the current sensors’ capability.