Model development and maintenance services

Meteorological Institute, University Bonn

Harrie-Jan Hendricks Franssen
Agrosphere, Forschungszentrum Jülich

Yaping Shao
Institute for Geophysics and Meteorology, University of Cologne

In the TR32, the modelling aspect constitutes one of three methodological pillars to better understand patterns and structures in the soil-vegetation-atmosphere (SVA) system, which will ultimately lead to better predictions.

In the long term perspective, the modelling activities taking place within the TR32 aim to provide and maintain a physically-based, modular modelling platform of the complete SVA system, which is able to handle multiple time and space scales and to assimilate measurements in an optimal way.

The goal of the project section Z4 is to provide modelling services with regard to maintenance and archiving, and to technically establish a simulation platform, which integrates developments from various project sections across the TR32 into one unified yet flexible modelling system. Thus, Z4 is central in reaching the scientific objectives of the TR32. The modelling platform will consist of the regional climate and weather forecast model COSMO coupled with the Community Land Model (CLM), which has been identified as the state-of-the-art parameterization scheme of land surface processes during the first phase. Additionally the variably saturated groundwater flow model ParFlow will be integrated to obtain a realistic interaction of groundwater flow with land surface processes. The advantage of a centrally managed project is

• a technically sound implementation of advanced parameterizations developed by various TR32 project sections and of strategies for coupling of different model components,
• a coordinated software development and maintenance that prevents duplication of efforts across individual project sections, and ensures a professional development infrastructure (version control, consistent updates, etc.),
• the creation of a simulation platform in the public domain that is available across different computational environments to many TR32 project sections and the national/international scientific community,
• a unified testing and validation of new parameterizations developed in various TR32 project sections,
• a smooth interfacing with data assimilation and optimization algorithms,
• a centrally managed flexible adaptation of input data (on arbitrary computational grids).

Figure 1: Schematic of the coupled modelling platform ParFlow-CLM- COSMO. The meteorological component COSMO operates on a 1 km scale, while the underlying land-surface and groundwater components CLM and ParFlow resolve surface and subsurface heterogeneities at a 100 m scale or finer.