Global downscaling of the 50-km MERRA2 reanalysis to 12.5-km with GEOS-5: Assessment

The GEOS-5 "replay" capability is used to produce a 15-year downscaled global reanalysis product at 12.5km using a non-hydrostatic version of the GEOS-5 atmospheric model. The adopted methodology allows us to closely follow the trajectory of the large-scales (effectively T60) in the underlying MERRA2 reanalysis, while allowing the downscaling model to embed in it its own, internally developed, mesoscale organization. This allows us to directly compare the simulated mesoscale with observations for specific synoptic situations. We will evaluate the downscaled reanalysis against high-resolution observations, focusing on the structure of mesoscale systems and the strength and structure of tropical cyclones.