Progress in regional reanalyses of DWD and their use in energy applications

Germany’s national meteorological service (Deutscher Wetterdienst, DWD) has initiated the development of a regional reanalysis more than a decade ago by establishing the Hans Ertel Centre for Weather Research (HErZ), which has one focus on climate monitoring. The development of a reanalysis system is the major tool for that focus activity. The development was carried outat the meteorological institutes of the Universities of Bonn and Cologne. Based on the numerical weather prediction model COSMO of DWD, regional reanalysis datasets have been developed with grid spacing of up to 2 km (Bollmeyer et al., 2015; Wahl et al., 2017). Esp. COSMO-REA6, a reanalysis for the EURO-CORDEX domain with 6 km spatial resolution has been made available under an open-data policy and has been used in a number of applications, esp. related to renewable energies (Kaspar et al., 2019). As the production relied on ERA-Interim boundary conditions, the production ended in 2019, but a second generation (“R6G2”, with boundary conditions from ERA5) is currently produced. Also, a reanalysis based on DWD’s new NWP system ICON is being prepared. Electricity generation with wind and solar is weather-dependent and the shift towards increased use of renewable energy leads to an increased need towards high quality meteorological data. In order to support the usage of DWD’s reanalysis data in energy-related applications, the project MEDAILLON has been started together with partners with specialized expertise in energy system analysis (MEDAILLON: “Generierung eines offenen meteorologischen Datensatzes mit zeitlich und räumlich hoher Auflösung für die Energiesystemanalyse und -wirtschaft”, coordinated by Fraunhofer IEE: https://www.iee.fraunhofer.de/de/projekte/suche/2023/medaillon.html). The aim is to better understand the user requirements and to provide optimized user-oriented products for energy applications. This includes an assessment of the quality of the relevant parameters. Previous experience has shown that users are especially interested in wind parameters from the reanalysis datasets. For solar radiation, also satellite-based products are an alternative, as e.g. the new version of the CM SAF-SARAH-dataset (also produced at DWD, most recent version is 3.0). The datasets are also applied in climate services of DWD, as e.g. in support of offshore wind planning in Germany’s Exclusive Economic Zone or in studies related to the potential of renewable energies alongside the German transportation infrastructure. In the presentation, we will summarize the current status of reanalysis activities at DWD and present the approach of MEDAILLON to derive user-friendly products.