Assimilation of cloud-affected satellite observations in idealized experiments of summer-time convection
We investigate the potential impact of cloud-affected satellite observations in the infrared and visible range using idealized observing system simulation experiments (OSSEs) with the convection-permitting COSMO-KENDA ensemble data assimilation system of Deutscher Wetterdienst (DWD). The experiments are performed for an idealized case of summer-time convection in central Europe and both the model and the observation operator are assumed to exhibit no systematic errors.
The results demonstrate that an LETKF data assimilation scheme is able to strongly benefit from cloud-affected satellite observations in the absence of systematic model and operator errors. Nearly all verification metrics including precipitation scores show a beneficial impact of the observations for lead times up to 6 h. Infrared brightness temperature shows a larger impact than visible channels, but the best forecasts are achieved by assimilating both types.
Dr. Martin Weissmann DWD / LMU