@misc{anders_evaluation_report_2024, 
author={Anders, Ivonne,Brienen, Susanne,Bucchignani, Edoardo,Demuzere, Matthias,Ferrone, Andrew,Geyer, Beate,Keuler, Klaus,Lüthi, Daniel,Mertens, Mariano,Osterried, Katja,Panitz, Hans-Jürgen,Saeed, Sajjad,Soerland, Silje,Schulz, Jan-Peter,Wouters, Hendrik},
title={Evaluation Report COSMO-CLM5.0},
year={2024},
howpublished = {report},
doi = {https://doi.org/10.5281/zenodo.14515358},
abstract = {The regional climate model COSMO-CLM is a community model (www.clm-community.com). In close collaboration with the COSMO-consortium the model is further developed by the community members for climate applications. One of the tasks of the community is to give a recommendation on the model version and to evaluate the models performance. 
The COPAT (Coordinated Parameter Testing) initiative is a voluntary community effort to carry out model simulations systematically by different institutions in order to test new model options and to find a satisfactory model setup for hydrostatic climate simulations over Europe. We will present the COPAT method used to achieve the latest recommended model version of COSMO-CLM (COSMO5.0_clm6). 
The simulations cover the EURO-CORDEX domain at two spatial resolutions 0.44° and 0.165°. They are forced by ERAinterim data for the time period of 1979-2000. Interpolated forcing data has been prepared once to ensure that all participating groups used identical forcing. The evaluation of each individual run has been performed for the time period 1981-2000 by using ETOOL and ETOOL-VIS. These tools have been developed within the community to evaluate standard COSMO-CLM output in comparison to observations provided by EOBS and CRU. 
The COPAT procedure was structured into 6 phases. In the Pre-Phase a group of institutions volunteered to contribute, a wiki has been setup, the forcing has been prepared and reference simulations at DKRZ have been performed. Furthermore, evaluation measures had been fixed and the necessary tools developed. In Phase 1 all participating institutions performed a reference run on their individual computing platforms and tested the influence of single model options on the results afterwards. Derived from the results of Phase 1 the most promising options were used in combinations in the second phase (Phase 2). These first two phases of COPAT consist of more than 70 simulations with a spatial resolution of 0.44°. Based on the best setup identified in Phase 2 a calibration of eight tuning parameters has been carried out following Bellbrat et al. (2012) in Phase 3. A final simulation with the calibrated parameters has been set up in Phase 4 at a higher resolution of 0.165°. The results were compared to previous model versions. The new model version COSMO5.0_clm6 led to the same or better results and therefore had been defined in the Final Phase as the new recommended model version of the community.},
note = {Online available at: \url{https://doi.org/10.5281/zenodo.14515358} (DOI). Anders, I.; Brienen, S.; Bucchignani, E.; Demuzere, M.; Ferrone, A.; Geyer, B.; Keuler, K.; Lüthi, D.; Mertens, M.; Osterried, K.; Panitz, H.; Saeed, S.; Soerland, S.; Schulz, J.; Wouters, H.: Evaluation Report COSMO-CLM5.0. 2024. DOI: 10.5281/zenodo.14515358}}