Development of Regional Reanalyses in Germany: 12 years of cross-community cooperation
Authors: Kaspar Frank , Keller Jan 
Published: June 2022

&lt;p&gt;The focus topic of this year's EMS meeting emphasizes the role of transdisciplinary consortia and collaborations - such as the German Hans Ertel Centre for Weather Research (HErZ). The development process of a regional reanalysis in Germany has relied strongly on such a cooperative approach with the site of this year's meeting - University of Bonn - together with the University of Cologne and Germany&amp;#8217;s national meteorological service (DWD) contributing to this success in particular.&lt;/p&gt;&lt;p&gt;The development of a regional reanalysis based began approx. 12 years ago as a fundamental research activity within the Hans Ertel Centre for Weather Research (HErZ) at the meteorological institutes of the Universities of Bonn and Cologne. Based on the numerical weather prediction model COSMO of DWD (Deutscher Wetterdienst), regional reanalysis datasets have been developed with grid spacing of up to 2&amp;#8201;km (Bollmeyer et al., 2015; Wahl et al., 2017). This activity was based on research funding provided by DWD and was conducted in close cooperation with DWD. Later, DWD included the reanalysis in its climate service portfolio and began working on its further development. The cooperation with European partners, esp. some national weather services, within the EU-FP7-project UERRA provided the opportunity to compare the quality of the COSMO-reanalysis with other products (Kaiser-Weiss et al., 2019). Today, COSMO reanalyses are an established product of the DWD and have been widely used in applications on European and national German levels. The COSMO reanalysis datasets are publicly available and provide spatio-temporal consistent data of atmospheric parameters covering both near-surface conditions and vertical profiles. A second generation of the COSMO reanalysis is currently in production and a reanalysis with DWD&amp;#8217;s new modeling system ICON is being prepared. Product evaluation is carried out in various collaborative projects, e.g. with focus on meteorological risk estimates or energy applications (Kaspar et al., 2019).&lt;/p&gt;&lt;p&gt;The dataset is used to support our partner agency BSH (Federal Maritime and Hydrographic Agency) in their tasks related to the expansion of wind farms within the German Exclusive Economic Zone (EEZ), as we will discuss in further presentations. Given the high relevance of high-quality weather information in the field of energy meteorology, cooperation with the Institute of Energy Economics at the University of Cologne (EWI) was also intensified in the current phase of the HErZ. The spatial and temporal resolution also provides opportunities to assess details of extreme events in various parameters, as it is done, for example, in the ClimXtreme research network, a cooperative activity of 35 research institutions coordinated by the University of Bonn. Through such cooperation with universities, the reanalysis has also been used in a number of theses.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References:&lt;/strong&gt;&lt;/p&gt;&lt;ul&gt;&lt;li&gt;Bollmeyer et al.: https://doi.org/10.1002/qj.2486.&amp;#8194;&lt;/li&gt;
&lt;li&gt;Kaiser-Weiss et al.: https://doi.org/10.1088/2515-7620/ab2ec3.&lt;/li&gt;
&lt;li&gt;Kaspar et al.: https://doi.org/10.5194/asr-17-115-2020.&lt;/li&gt;
&lt;li&gt;Wahl et al.: https://doi.org/10.1127/metz/2017/0824.&amp;#8194;&lt;/li&gt;
&lt;/ul&gt;