C-Coupler1: a Chinese community coupler for Earth system modeling

Abstract. A coupler is a fundamental software tool for Earth system modeling. Targeting the requirements of 3-D coupling, high-level sharing, common model software platform and better parallel performance, we started to design and develop a community coupler (C-Coupler) from 2010 in China, and finished the first version (C-Coupler1) recently. C-Coupler1 is a parallel 3-D coupler that achieves the same (bitwise-identical) results with any number of processes. Guided by the general design of C-Coupler, C-Coupler1 enables various component models and various coupled models to be integrated on the same common model software platform to achieve a higher-level sharing, where the component models and the coupler can keep the same code version in various model configurations for simulation. Moreover, it provides the C-Coupler platform, a uniform runtime environment for operating various kinds of model simulations in the same manner. C-Coupler1 is ready for Earth system modeling, and it is publicly available. In China, there are more and more modeling groups using C-Coupler1 for the development and application of models.