UGWP Physics Package

How to use the UGWP physics package in MPAS

The Unified Gravity Wave Physics (UGWP) scheme is adapted from the CCPP library. A description of the scheme can be found here

NOTE: In the documentation below, the string xxxx is a wildcard place holder for the designation of your mesh, e.g., x1.10242 for the 240km uniform global mesh, or hrrrv5_mpas for a regional mesh.

I. Creating static orographic data file for your mesh — xxxx.ugwp_oro_data.nc

1. Make sure you have the file xxxx.grid.nc in your directory. This file contains the necessary cell lat/lon and cell area data.

2. Configure the streams.init_atmosphere file as follows:

<immutable_stream name="input"
                  type="input"
                  filename_template="xxxx.grid.nc"
                  input_interval="initial_only" />

<immutable_stream name="output"
                  type="output"
                  filename_template="xxxx.static.nc"
                  packages="initial_conds"
                  output_interval="initial_only" />

<immutable_stream name="ugwp_oro_data"
                  type="output"
                  filename_template="xxxx.ugwp_oro_data.nc"
                  output_interval="initial_only" />

Note that the execution of init_atmosphere_model in step 4 creates the xxxx.static.nc file as well as the xxxx.ugwp_oro_data.nc. If you already have the xxxx.static.nc file, save it somewhere and replace the newly created static file with it if desired.

3. In the namelist.init_atmosphere file, you'll need:

&preproc_stages
    config_static_interp = true
    config_native_gwd_static = false
    config_native_gwd_gsl_static = true

4. Run init_atmosphere_model. Check that the file xxxx.ugwp_oro_data.nc file was created.

II. Running the atmosphere model with the UGWP physics package.

1. Make sure you have the xxxx.ugwp_oro_data.nc file in your run direcotry.

2. Include the following lines in your streams.atmosphere file:

<immutable_stream name="ugwp_oro_data_in"
                  type="input"
                  filename_template="x1.10242.ugwp_oro_data.nc"
                  input_interval="initial_only" />

3. In the namelist.atmosphere file, include the following line in the &physics section of the namelist:

config_gwdo_scheme = 'bl_ugwp_gwdo'

4. Run atmosphere_model.

Instructions provided by Mike Toy, NOAA GSL