Reconstruction of annual mean wind speed statistics at 100 m height of FINO1 and FINO2 masts with reanalyses and the geostrophic wind

Abstract

This study deals with the reconstruction of wind speed from reanalyses and the geostrophic wind in the German Bight (FINO1) and the Western Baltic Sea (FINO2). The reconstruction is done with the help of a linear regression based on correlations between measurements and reanalyses. The data are the datasets of the FINO1 and FINO2 stations at 100 m height from the Federal Maritime and Hydrographic Agency (Bundesamt fur Seeschifffahrt und Hydrographie, BSH) as well as the reanalyses COSMO REA6, ERA5 and Twentieth Century Reanalysis version 3 (20CRv3). Furthermore, surface pressure data from the archives of the German Meteorological Service (DWD) at six stations, from which the geostrophic wind is calculated at the FINO1 and FINO2 stations, are used. The geostrophic wind in the German Bight and the Western Baltic Sea is calculated by triangular interpolations using pressure and stratif cation at three neighboring stations. To determine the relation between the datasets, the hourly measurements of all datasets are used, except for the analysis with 20CRv3, which uses the three-hourly values. The analyses are carried out for the period 2004-2009 for FINO1 and 2008-2014 for FINO2. The results show that the regression analyses are suitable for the reconstruction of wind speed data and more consistent than those of the geostrophic wind, which may serve as a f rst approximation.