CM1

The Cloud Model version 1 is a mesoscale atmospheric model that allows for idealized studies of atmospheric phenomena. A new Lagrangian microphysics capability has been added which enables a significantly more accurate representation than the traditional bulk or multi-moment approaches frequently found in mesoscale atmospheric models. We have utilized a directive-based approach to enable a single source code to efficiently support the execution of CM1 on both CPU and GPU-based computing platforms. In addition to the use of accelerator directives, changes to the index search scheme and the message-passing algorithms used by the lagrangian microphysics were necessary to enable efficient execution. We focus on a configuration of CM1 that will be used to investigate the impact of oceanic sea spray on the atmospheric boundary layer within a hurricane. We observe a factor of 2.9x reduction in time to the solution when between eight NVIDIA A100 GPUs and eight AMD Epyc based compute nodes

CM1 is a product of the National Center for Atmospheric Research’s MMM Lab. Support for CM1 is provided by the U.S. National Science Foundation