Installing WRF-GC

System Requirements

WRF-GC requires a set of compilers & libraries that are compatible with the WRF model & the GEOS-Chem High Performance model.

Recommended system setup (as tested): - Compiler: Intel 15. - MPI Library: MVAPich2 Version 2.3 (http://mvapich.cse.ohio-state.edu/downloads/) - zlib (http://www.zlib.net/) - HDF5 1.8 (https://support.hdfgroup.org/HDF5/release/obtainsrc518.html) - NetCDF-C 4.6.1 (https://www.unidata.ucar.edu/downloads/netcdf/index.jsp) - NetCDF-Fortran 4.4.4 - JasPer 1.900.29 (https://www.ece.uvic.ca/~frodo/jasper/#download)

It is recommended to install all libraries in the same location (using the --prefix=/your/directory/here when calling the configure script). For WRF to correctly find those libraries, you need to set the HDF5 & NETCDF environmental variables to point to the directory (which includes the bin, lib, include directories) where those libraries are installed.

Obtain the WRF model and the WPS pre-processing system. Recommended version is WRF v3.9.1.1. Only WRF version 3.9+ is supported as it provides the hybrid sigma-eta vertical grid functionality required by GEOS-Chem. Version 4.0 is supported but requires modifications to the code. Please refer to: • WRF User’s Guide: http://www2.mmm.ucar.edu/wrf/users/docs/user_guide_V3.9/users_guide_chap1.htm • Download Page: http://www2.mmm.ucar.edu/wrf/users/downloads.html

Obtain the GEOS-Chem model and WRF-GC interface. After downloading the WRF model, go into the WRF or WRFV3 directory (depending on your WRF version). In the folder where arch, dyn_em, main … folders are located in, use the following command to check-out the WRF-GC source code repository into the “chem” folder:

``` to be available soon ```

As of time of writing, the WRF-GC interface’s bundled version of GEOS-Chem is GEOS-Chem 12.2.0.

Installing WRF-GC

Please refer to the WRF User’s Guide for installation, taking note that: • Set the NETCDF, HDF5 environment variables, JASPERLIB and JASPERINC to the respective “lib” and “include” directories, and WRF_EM_CORE to 1, WRF_NMM_CORE to 0, WRF_CHEM to 1.

• The configure command must include the hybrid grid option: ./configure -hyb

• Choose the distributed-memory parallel (dmpar) version of WRF, with Intel C & Fortran compilers

• Before compiling, go into the “chem” subdirectory and install the WRF-GC registry: make install_registry

• Compile WRF-GC like WRF-Chem: ./compile em_real