Changes between Version 9 and Version 10 of WRF4G2.0/Geogrid
 Timestamp:
 Oct 7, 2015 12:21:35 PM (6 years ago)
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WRF4G2.0/Geogrid
v9 v10 5 5 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 WRFARW 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.). 6 6 7 Here we are going to explain the variables that usually need modification and we will show an example for 2nesting domain:7 Variables that usually need modification and we will show an example for 2nesting domain: 8 8 9 * parent_id >List of integers specifying the domain number of the nest’s parent (One per domain).9 * '''parent_id:''' List of integers specifying the domain number of the nest’s parent (One per domain). 10 10 11 11  parent_id=1,1 12 * parent_grid_ratio >It is a list of integers specifying for each domain the nesting ratio relative to the domain's parent.12 * '''parent_grid_ratio:''' It is a list of integers specifying for each domain the nesting ratio relative to the domain's parent. 13 13 14 14  parent_grid_ratio=1,3 15 * i_parent_start, j_parent_start >Coordinates of the lower left corner of the nest in the domain's parent.15 * ''''i_parent_start, j_parent_start:''' Coordinates of the lower left corner of the nest in the domain's parent. 16 16 17 17  i_parent_start=1,16, j_parent_start=1,34 18 * e_we >It represents the nest’s full westeast dimension. For nested domains, e_we must be one greater than an integer multiple of the nest's parent_grid_ratio18 * '''e_we:''' It represents the nest’s full westeast dimension. For nested domains, e_we must be one greater than an integer multiple of the nest's parent_grid_ratio 19 19 20 20  e_we=60,82 21 * e_sn >It represents the nest’s full southnorth dimension. For nested domains, e_sn must be one greater than an integer multiple of the nest's parent_grid_ratio.21 * '''e_sn:''' It represents the nest’s full southnorth dimension. For nested domains, e_sn must be one greater than an integer multiple of the nest's parent_grid_ratio. 22 22 23 23  e_sn=81,112 24 * dx >Number specifying the grid distance in the xdirection where the map scale factor is 1. It should be in meters for the 'polar', 'lambert', and 'mercator' projection, and in degrees longitude for the 'latlon' projection.24 * '''dx:''' Number specifying the grid distance in the xdirection where the map scale factor is 1. It should be in meters for the 'polar', 'lambert', and 'mercator' projection, and in degrees longitude for the 'latlon' projection. 25 25 26 26  dx=0.15 27 * dy >Number specifying the grid distance in the ydirection where the map scale factor is 1. As stated for dx, this value should be in meters for the 'polar', 'lambert', and 'mercator' projection, but for the 'latlon' projection, it should be in degrees latitude.27 * '''dy:''' Number specifying the grid distance in the ydirection where the map scale factor is 1. As stated for dx, this value should be in meters for the 'polar', 'lambert', and 'mercator' projection, but for the 'latlon' projection, it should be in degrees latitude. 28 28 29 29  dy=0.15 30 * map_proj >Name of the projections available 'lambert', 'polar', 'mercator', and 'latlon'30 * '''map_proj:''' Name of the projections available 'lambert', 'polar', 'mercator', and 'latlon' 31 31 32 32  map_proj='latlon' 33 * ref_x, ref_y >Location of the latitude and longitude of reference for the domain33 * '''ref_x, ref_y:''' Location of the latitude and longitude of reference for the domain 34 34 35 35  ref_x=1, ref_y=1 36 * ref_lat, ref_lon >Reference coordinates of the domain.36 * '''ref_lat, ref_lon:''' Reference coordinates of the domain. 37 37 38 38  ref_lat=8.85, ref_lon=24.1 39 * pole_lat >For the latitudelongitude projection, it represents the latitude of the North Pole with respect to the computational latitudelongitude grid in which 90.0° latitude is at the bottom of a global domain and 90.0° latitude is at the top.40 * pole_lon >For the latitudelongitude projection, it represents the longitude of the North Pole with respect to the computational latitudelongitude grid in which 180.0° longitude is at the center.41 * stand_lon >A real value specifying the longitude that is parallel with the yaxis in the Lambert conformal and polar stereographic projections. For the regular latitudelongitude projection, this value gives the rotation about the earth's geographic poles.42 * geog_data_path >Path to the directory where the geographical data directories may be found.39 * '''pole_lat:''' For the latitudelongitude projection, it represents the latitude of the North Pole with respect to the computational latitudelongitude grid in which 90.0° latitude is at the bottom of a global domain and 90.0° latitude is at the top. 40 * '''pole_lon:''' For the latitudelongitude projection, it represents the longitude of the North Pole with respect to the computational latitudelongitude grid in which 180.0° longitude is at the center. 41 * '''stand_lon:''' A real value specifying the longitude that is parallel with the yaxis in the Lambert conformal and polar stereographic projections. For the regular latitudelongitude projection, this value gives the rotation about the earth's geographic poles. 42 * '''geog_data_path:''' Path to the directory where the geographical data directories may be found. 43 43 44 44  geog_data_path='$HOME/WRF/wps_topo/geog' 45 45 46 46 Also, the GEOGRID.TBL file is needed to be present into a folder called geogrid, in the same place where geogrid is going to be executed. The final structure is the following: 47 48 47 {{{ 49 #!sh50 [user@mycomputer~]$ tree51 .52 48  geogrid 53 49  ` GEOGRID.TBL … … 55 51 }}} 56 52 57 58 Provided the namelist and the GEOGRID.TBL, the next step is to execute geogrid.exe. This will generate a netCDF file called geo_em_d01.nc, which contains all the fixed fields that WRF needs to run with that domain. 59 53 Provided the namelist and the `GEOGRID.TBL`, the next step is to execute `geogrid.exe`. This will generate a netCDF file called `geo_em_d01.nc`, which contains all the fixed fields that WRF needs to run with that domain. 60 54 {{{ 61 55 #!sh