[10-4]

Assimilation of visible and near-infrared satellite observations in KENDA-COSMO

Leonhard Scheck (HErZ, LMU Munich), Tobias Necker (HErZ, LMU Munich), Pascal Frerebeau (LMU Munich), Bernhard Mayer (LMU Munich), Martin Weissmann (HErZ, LMU Munich)

Satellite observations contain a wealth of information about convective activity and are therefore seen as important input parameters for convective scale data assimilation (DA). However, current operational DA systems in general utilize only clear sky thermal infrared and microwave radiance observations, which mainly provide temperature and humidity information. Due to the lack of suitable forward operators, visible and near-infrared radiances, which contain information about cloud properties, are not considered.

To address this shortcoming, a fast forward operator for visible and near-infrared reflectance observations from MSG-SEVIRI is currently in development. A preliminary version of the operator has been completed and implemented in the pre-operational km-scale Ensemble Data Assimilation (KENDA) system of DWD. The operator simulates synthetic satellite images from COSMO-DE model output and relies on a loop-up table based method that is sufficiently accurate and orders of magnitude faster than conventional radiative transfer solvers for the visible spectrum. We present this novel operator and first results from assimilation experiments.