Assessment of new DWD and Copernicus regional reanalysis products R6G2 and CERRA with focus on near surface wind speed

Reanalyses are enjoying an ever-increasing number of users and interest groups, especially due to steadily increasing spatial and temporal resolutions. However, new applications also require a comprehensive quality assessment of the used data set, taking into account different time scales, parameters, and regions. Within the framework of the joint BMBF project ClimXtreme (https://www.climxtreme.net/), we evaluate the quality of DWD’s current reanalysis product COSMO-REA6 and its follow-up product R6G2 (COSMO-REA6 Generation 2) concerning the representation of extreme events like heat waves, windstorms and heavy precipitation.

Reanalyses enable a comprehensive assessment of extreme events and their relevant processes. Here we are aiming at an evaluation approach of extreme wind events and comparisons for mean near surface wind speed, analyzing sub-daily, daily and seasonal patterns, as well as regional differences. The comparisons (using station measurements and gridded observations as reference as well as known reanalyses such as ERA5 as benchmark) also integrate brand new data from the Copernicus European Regional Re-Analysis (CERRA). Both regional reanalyses, CERRA and R6G2 are available for the complete EURO-CORDEX domain, at an almost similar spatial resolution of 5.5 km for CERRA and about 6 km for R6G2. The evaluation here, concentrate on the German region and current events from the years 2018, like winter storm Friederike.

For evaluation the platform MAVIS (Meteorological Analysis and Visualization System), based on Freva (http://doi.org/10.5334/jors.253) is used. Freva is a scientific software framework supporting scientific cooperation on high performance computing environments, equipped with a standardized model database, a programming interface and a history of evaluations.