View source for Running WRF-GC

The process of running WRF-GC is very similar to running WRF-Chem. 


=Running the WPS=

Running the WRF Preprocessing System (WPS) is to prepare input to drive WRF. Please refer to the [http://www2.mmm.ucar.edu/wrf/users/docs/user_guide_V3.9/users_guide_chap3.html WRF User's Guide] for more detail: 



==Step 1: Define model domains with geogrid==
        
:In the "geogrid" namelist record, the projection of the simulation domain is defined. Only two possible map projections and specified parameters are supported in WRF-GC:

:•	Mercator /'mercator'   (truelat1)

:•	Unrotated regular latitude-longitude /'lat-lon'   (pole_lat, pole_lon, stand_lon) 



==Step 2: Extracting meteorological data from GRIB files with ungrib==

:Downloading meteorological data for the real data case
 
:•	http://www2.mmm.ucar.edu/wrf/users/download/free_data.html


==Step 3: Horizontally interpolating meteorological data with metgrid==





=Preparing GEOS-Chem shared data directories=

The GEOS-Chem shared data directories contain many large files necessary for the WRF-GC. Please Set up the top-level root directory for GEOS-Chem shared data, which is called '''ExtData'''. Please create the '''/dir/to/data/ExtData''' and set your directories in the ''"input.geos"'' file:

        Root data directory : /dir/to/data/ExtData


The ExtData directory structure cotains two subdirectories:


-	CHEM_INPUT: Non-emissions data for GEOS-Chem chemistry modules

:•	Download the CHEM_INPUT data directories via anonymous FTP from the Harvard data directory archive (ftp.as.harvard.edu). Please refer to : http://wiki.seas.harvard.edu/geos-chem/index.php/Downloading_GEOS-Chem_source_code_and_data


-	HEMCO: Emissions inventories for the HEMCO emissions component

:•	Download the HEMCO data directories with a pakeage provided by GEOS-Chem Support Team. Please refer to : http://wiki.seas.harvard.edu/geos-chem/index.php/HEMCO_data_directories#Downloading_the_HEMCO_data_directories


:•	Set the HEMCO data directory in the ''"HEMCO_Config.rc"'' file

        Root : /dir/to/data/ExtData/HEMCO


=Emissions for WRF-GC=

Preparing emission files is not required. WRF-GC uses the Harvard-NASA Emissions Component (HEMCO) with on-line regridding. Configure HEMCO refer to the ''"HEMCO_Config.rc"'' file inside the run directory for WRF. For more information on HEMCO data directories, please refer to [http://wiki.seas.harvard.edu/geoschem/index.php/HEMCO_data_directories the GEOS-Chem wiki]: 



=Preparing chemical initial/boundary condition data=

Chemical initial and boundary condition data are used output from global simulation MOZART-4/GEOS-5 similar to WRF-Chem. Please download the data from :

•	https://www.acom.ucar.edu/wrf-chem/mozart.shtml


The Mozart data are processed by the WRF-Chem processor called '''mozbc'''. Please download the mozbc utility, including instructions and input files from :

•	https://www.acom.ucar.edu/wrf-chem/download.shtml



=Running WRF-GC=

To Configure WRF-GC, you need to edit three files inside the WRF run directory.

-	'''''HEMCO_Config.rc''''' (Please refer to: http://wiki.seas.harvard.edu/geos-chem/index.php/GEOS-Chem_Input_Files#The_HEMCO_Config.rc_file)

:•	''HEMCO_Config.rc'' file contains a set of switches to enable and disable emission inventories, such as:

       # ExtNr ExtName           on/off  Species
       0       Base              : on    *
           --> HEMCO_RESTART     :       false
           --> AEIC              :       true
           --> BIOFUEL           :       true
       ... etc not shown here ...


:•	Errors with HEMCO component when running a simulation are output into a log file called ''"HEMCO.log"''.


-	'''''input.geos'''''

:•	Simulation Menu (except '''Root data directory''') and Timestep Menu in ''input.geos'' can be safely ignored.


:•	Determine the Advected Species Menu, Transport Menu, Convection Menu, Emission Menu, Aerosol Menu, Deposition Menu and Chemistry Menu according to your specific simulation (Please refer to : http://wiki.seas.harvard.edu/geos-chem/index.php/GEOS-Chem_Input_Files).


:•	Other Menus in ''"input.geos"'' can be safely ignored.


-	'''''namelist.input'''''

....available soon....

To run WRF-GC, use the distributed-memory parallel version of WRF's real.exe and wrf.exe, like -

        mpirun -np 6 ./wrf.exe


To monitor output from WRF&GEOS-Chem, you can tail the ''"rsl.out.000"'' file:

        tail -f rsl.out.0000


Output from WRF&GEOS-Chem are unified into the WRF output format (NetCDF Classic) files starting with ''wrfout''.