# Changes between Version 5 and Version 6 of WRF4G2.0/Geogrid

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Timestamp:
Oct 7, 2015 12:00:27 PM (7 years ago)
Comment:

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Unmodified
 v5 The step of the WRF Preprocessor System (WPS), called [http://www2.mmm.ucar.edu/wrf/OnLineTutorial/Basics/GEOGRID/index.html geogrid], is not included in the WRF4G workflow. Thus, the user has to deal with it by hand, or using another tool, such as [http://esrl.noaa.gov/gsd/wrfportal/DomainWizard.html WRF Domain Wizard]. Geogrid does the task of extracting the fixed fields (orography, land use data, etc.) that WRF needs to run at a given resolution and region. In the WRF4G framework, the output of geogrid is known as the domain of an experiment. Inside the original WRF4G tarball there are two example domains, Santander_50km and wrfuc, located in \$WRF4G_DEPLOYMENT_DIR/repository/domains. Here, we are going to see how a new one can be added. It is important to note that it exists an [http://www2.mmm.ucar.edu/wrf/OnLineTutorial/index.htm excellent on-line tutorial] for running WPS and WRF by hand. Users of WRF4G are encouraged to work through this tutorial before start running with WRF4G itself. This framework is intended to make life much easier for WRF users, but knowledge about WRF itself is needed to deal with common errors and issues, and to carry on a correct interpretation of the results. First of all, WPS binaries are needed. If you don't have them in your system, you will need to build them from source. Instructions for doing this are available too in the [http://www.mmm.ucar.edu/wrf/OnLineTutorial/Compile/index.html WRF-ARW online tutorial]. Once you have the binaries, you will need to prepare a namelist.wps file defining your requirements for the domain (e.g. size, location, resolution, etc.) Here we are going to explain the variables that usually need modification and we will show an example for 2-nesting domain. First of all, WPS binaries are needed. If you don't have them in your system, you will need to build them from source. Instructions for doing this are available too in the [http://www.mmm.ucar.edu/wrf/OnLineTutorial/Compile/index.html WRF-ARW online tutorial]. Once you have the binaries, you will need to prepare a namelist.wps file defining your requirements for the domain (e.g. size, location, resolution, etc.). Here we are going to explain the variables that usually need modification and we will show an example for 2-nesting domain: * parent_id --> List of integers specifying the domain number of the nest’s parent (One per domain).