High Performance GEOS-Chem (GCHP) is a hybrid version of the standard GEOS-Chem code (GEOS-Chem Classic) that includes an additional software layer consisting of the Earth System Model Framework (ESMF) and Message Passing Interface (MPI) parallelization libraries. It enables distributed memory execution in high-performance computing (HPC) environments. This will facilitate global GEOS-Chem simulations at extremely fine horizontal resolution (e.g. 0.25°).
GCHP has the following advantages over the GEOS-Chem Classic model:
Multi-node architecture: As GCHP uses MPI rather than OpenMP for parallelization, it can be run on an arbitrary number of cores, and over an arbitrary number of machines.
Ultra-fine resolution global simulations: Without the memory limits of a single-machine architecture, the only limit on GCHP is the resolution of your input data.
No more polar singularity: GCHP uses the "cubed-sphere" geometry for all operations, leveraging the GFDL FV-cubed (FV3) transport core. This avoids the polar singularity inherent to regular lat-lon grids.
HEMCO used for all inputs: Every initial and boundary condition is now read from NetCDF files through HEMCO. This means that all data, including met data, can be regridded on the fly.
Grid-independent compile process: Grid resolution is set at run time, and no recompilation is required.
For more information about GCHP, including how to download the publicly available GCHP Dev Kit, please visit the main GEOS-Chem HP development wiki page.