Researches on planetary atmospheres using numerical models and GFD-Dennou Club DCMODEL project

Space missions for planetary atmospheres and numerical simulations are fundamental components for researches on planetary atmospheres. Recently, numerical simulation models become essential to planning of missions, analyzing and providing observational data. On the other hand, the simulation models used in these researches have become so expanded and complicated that it is dif.cult for one researcher to understand, develop, maintain and provide their source codes. "Model gap problem"is one of the dif.culties with numerical simulation models. In order to check the validity of the simulation models and to develop them further, it is necessary to perform numerical calculations with numerical models with various complexities and to compare the numerical results mutually. Expansion of the simulation models makes dif.cult to perform such inter-comparison for checking of the validity. In an attempt to overcome the "model gap problem", we have been proceeding"dcmodel project", where a series of hierarchical numerical models with various complexity is developed and maintained as a voluntary activity. The numerical models are developed with the following intentions: 1) Hierarchical models with various complexities. 2) Common"style" of programming in order to ensure readability. 3) Open source codes to the public. 4) Scalability of the models in order to ensure execution on various platforms. 5) Stressing the importance of documentation and presenting a method for producing reference manuals. The series of hierarchical models enable us to conduct multiple numerical experiments with multiple models easily, which will lead to a deeper understanding of various phenomena in planetary atmospheres.