Downloading WRF-GC

This section discusses:

Downloading the WRF model.
Downloading the WRF-GC coupler and the GEOS-Chem model.
Downloading the WPS (WRF Pre-Processor).

Note

Currently, the GEOS-Chem model is included within the WRF-GC coupler. In the future, we plan to distribute these separately.

However, the GEOS-Chem model version within the WRF-GC coupler, located within the gc folder, is unmodified. You can change this copy of GEOS-Chem just as you would change any other copy of GEOS-Chem, for your research.

Warning

Do not move the WRF-GC directory after compiling, even on the same machine. Do not share a compiled copy of WRF-GC with others because during the compile process, the file paths are fixed. Always install a fresh copy of WRF and download the WRF-GC into the chem directory when you move folders!

Choose a folder to store your WRF-GC model, then proceed with the steps below.

Downloading WRF

Obtain the WRF model from the NCAR/WRFV3 GitHub (version 3.9.1.1 for WRF-GC v1.0 and v2.0) or the wrf-model/WRF GitHub (version 4.0 and above for WRF-GC v3.0)

For WRF-GC v1.0 and v2.0, use WRF version 3.9.1.1

wget https://github.com/NCAR/WRFV3/archive/refs/tags/V3.9.1.1.zip
unzip V3.9.1.1.zip

Extract WRF into the WRFV3 folder (version 3). For simplicity, we refer to the folder as WRF below.

For WRF-GC v3.0, use WRF version 4.3 or 4.4

wget https://github.com/wrf-model/WRF/releases/download/v4.4/v4.4.zip
unzip v4.4.zip

Extract WRF into the WRFV4.X folder (version 4), and rename it to WRF.

Downloading the WRF-GC coupler and GEOS-Chem model

For WRF-GC v3.0

Go into the WRF folder and delete the existing WRF-Chem chemistry. Delete the chem folder entirely.
Clone the WRF-GC repository into the chem folder. After April 22, 2024, the default release downloaded is version 3.0.

git clone https://github.com/WRF-GC/wrf-gc-release.git chem

For WRF-GC v2.0 (older, not recommended)

Go into the WRF folder and delete the existing WRF-Chem chemistry. Delete the chem folder entirely.
Clone the WRF-GC repository into the chem folder.

git clone https://github.com/WRF-GC/wrf-gc-release.git chem

In the chem folder, choose the older WRF-GC 2.0:

cd chem
git checkout v2.0

After downloading

Make sure you have the right code in the chem folder. The folder should look like this:

WRF/chem$ ls
gc                config
chem_driver.F     module_chem_utilities.F    module_input_chem_data.F
chemics_init.F    module_convection_prep.F   module_data_rrtmgaeropt.F
wrfgc_convert_state_mod.F ...

Downloading the WPS Pre-Processor

Go outside the WRF folder and download WPS side-by-side with WPS, from the wrf-model/WPS GitHub. Download the version closest to your WRF version (3.9, 4.3, etc.)

Extract the WRF Pre-Processor.

Warning

If you are running simulations after July 2019, you have to use WPS version 4.0 or above. It works with WRF v3.9 as well. Refer to this post for details