WRF-Chem-v4.1-AFWA-Drag-Partition-Modifications: Initial full model code release

This repository contains modified Weather Research and Forecasting with Chemistry (WRF-Chem) Version 4.1 model code with Version 1.0 of the albedo-based drag partition parameterization originally developed by Chappell and Webb (2016, Aeolian Res.) incorporated into the AFWA dust emission module.

Instructions:

Download and compile the modified WRF-Chem code from the Drag_Partition_Modified_Code directory following the same build procedures required for setting up the baseline WRF-Chem code (see https://ruc.noaa.gov/wrf/wrf-chem/).

WRF-Chem v4.1 baseline source code and run instructions are available for download at https://github.com/wrf-model/WRF/releases/tag/v4.1.

To implement these changes into an existing copy of WRF-Chem v4.1, copy the .F files listed below from this repository to the corresponding WRF-Chem subdirectory (/Registry or /chem) and compile the WRF-Chem code. Note that because these steps include a change to the model registry, users will need to do a full clean of WRF-Chem (./clean -a) if these changes are being added to previously compiled code.

Files that differ from the WRF-Chem v4.1 baseline code and purpose:

• WRF-v4.1/Registry/registry.chem - file to add namelist variables
• WRF-v4.1/chem/chem_driver.F - passes u_ns* data to the AFWA dust emission module
• WRF-v4.1/chem/emissions_driver.F - passes u_ns* data to the AFWA dust emission module
• WRF-v4.1/chem/module_gocart_dust_afwa.F - AFWA dust emission module with drag partition code modifications

Though we used WRF-Chem v4.1 in this implementation example, the process should be relatively consistent for later WRF-Chem versions (currently on v4.4 at the time of publication). We recommend users planning to use the WRF-Chem/GOCART dust transport capability work with WRF-Chem v4.1 or later due to a critical bug fix in the GOCART deposition module.

Please refer to the technical report by Michaels et al. (2022; ERDC/CRREL TR-22-2) for detailed code descriptions, guidance on preparing the required input data, and model runtime instructions.

This repository also includes a copy of the WRF Pre-processing System (WPS) Version 4.2, obtained from https://github.com/wrf-model/WPS/releases/tag/v4.2. We used this version of WPS to generate terrain and atmospheric forcing condition inputs for simulations during our code implementation and testing process.