hh
Special Set-up Case for WRF-Var Participants
 

This is recommended for anyone that is also going to participant in the WRF-Var tutorial next week.
For this case we will use the Katrina Hurricane data.
Case dates are 2005-08-28_00 to 2005-08-30_00, and data are available 6-hourly.

 

Source Code

If you do not already have the code, then copy it from the source directory.

 

Set-up WPS

  • Make sure you are in the WPS directory.    
     
     
  • Edit namelist.wps to configure the simulation domain and produce input data files for the WRF model. We are going to create a single domain over central USA. The domain size will be 75x70 grid points, with a grid resolution of 30km. We will use a Lambert projection.
     
    • Make the following changes to the namelist:

          max_dom = 1,
          start_date = '2005-08-28_00:00:00',
          end_date = '2005-08-29_00:00:00',
          interval_seconds = 21600,
          e_we = 140,
          e_sn = 94,
          dx = 45000,
          dy = 45000,
          map_proj = 'mercator',
          ref_lat = 20.00
          ref_lon = -75.00
          truelat1 = 20.0,
          truelat2 = 20.0,
          stand_lon = -75.00
          geog_data_path = '/wrfhelp/GEOG_DATA/WPS_GEOG'

    • Some basic descriptions of the namelist variables are available from the OnLine Tutorial page (geogrid ; ungrib ; metgrid)
    • More detailed information is available in Chapter 3 of your ARW User's Guide
       
  • Run plotgrids.exe from the util/ directory to see where your grid is located:
     
         ./util/plotgrids.exe
     
         This program reads the grid location from namelist.wps (namelist record &geogrid) and creates a grid plot.
         Use the NCAR Graphics utility 'idt' to view the output (gmeta is a generic NCAR Graphics plot output name):
     
         idt gmeta  
     
         Click on the forward arrow. You should the domain below.

     

Run geogrid  

Configure model grid and generate geographical data file "geo_em.d01.nc" by running program geogrid.exe:
 
     ./geogrid.exe

 

Run ungrib

    Degrib and reformat meteorological data from another model, in this case, the data come from NCEP/GFS model.

    • Link the GRIB data using script file link_grib.csh:
       
           ./link_grib.csh /wrfhelp/DATA/Katrina/avn_05
            NOTE: There is no "." at the end of this command, as this is a script that is run.
                      Take care to link to files and NOT to a directory.

           We are using GFS GRIB version 1 data as input
       
    • Link the correct Vtable (the input data for this case is GFS, so use the GFS Vtable):
       
           ln -sf  ungrib/Variable_Tables/Vtable.GFS   Vtable
       
       
    • Ungrib the input data by running program ungrib.exe:
       
           ./ungrib.exe >& log.ungrib &
       
           This will create a number of files:
       
                FILE:2005-08-28_00
                FILE:2005-08-28_06
                FILE:2005-08-28_12
                FILE:2005-08-28_18
                FILE:2005-08-29_00

Run metgrid

Interpolating external model data to your model grid (created by geogrid), and create input data for WRF by running program metgrid.exe:
 
     ./metgrid.exe >& log.metgrid &
 
     This will create a number of files:
 
          met_em.d01.2005-08-28_00:00:00.nc
          met_em.d01.2005-08-28_06:00:00.nc
          met_em.d01.2005-08-28_12:00:00.nc
          met_em.d01.2005-08-28_18:00:00.nc
          met_em.d01.2005-08-29_00:00:00.nc
 
Try netcdf data browser 'ncview' to quickly examine your data files from metgrid.  


 

Set-up WRF

  • Make sure you are in the WRFV3 directory.    
     
     
  • cd to directory test/em_real
     
     
  • Edit the namelist.input file to reflect the domain / date information of the Colorado case:
     
         start_year = 2005,
         start_month = 08,
         start_day = 28,
         start_hour = 00,
         end_year = 2005,
         end_month = 08,
         end_day = 29,
         end_hour = 00,
         interval_seconds = 21600,
         history_interval = 180,
         max_dom = 1,
         e_we = 140,
         e_sn = 95,
         e_vert =57,
         num_metgrid_levels =27,
         dx = 45000,
         dy = 45000 ,
         p_top_requested=1000
         eta_levels= 1.00000,0.99730,0.99157,0.98506,0.97772,
                          0.96943,0.96010,0.94962,0.93789,0.92478,
                          0.91020,0.89403,0.87618,0.85657,0.83514,
                          0.81183,0.78664,0.75960,0.73078,0.70027,
                          0.66825,0.63491,0.60048,0.56527,0.52957,
                          0.49370,0.45802,0.42281,0.38842,0.35510,
                          0.32311,0.29265,0.26386,0.23686,0.21172,
                          0.18845,0.16706,0.14749,0.12968,0.11355,
                          0.09901,0.08593,0.07423,0.06378,0.05447,
                          0.04621,0.03888,0.03240,0.02668,0.02163,
                          0.01718,0.01328,0.00984,0.00682,0.00418,
                          0.00186,0.00000
     
    • How did we now to change 'num_metgrid_levels' to 27?
      Type 'ncdump -h met_em.d01.2005-08-28_00:00:00.nc | more' on the command line.
      Look for the 'num_metgrid_levels' in the dimension session of the output.
       
    • Add p_top_requested and eta_levels to the &domains section of your namelist - this si to conform to the special case which has been planned for the WRF-Var tutorial.
       
    • To learn more about the namelist variables view the OnLine Tutorial page, or
    • For more details, see Chapter 5 of your ARW User's Guide
       
       

Run real

  • Link the metgrid output data files from WPS to the current directory:
     
         ln -sf ../../../WPS/met_em* .
     
  • Run program real to produce model initial and lateral boundary files.
     
         mpirun -np 1 -machinefile ~/mach real.exe    
     
    This will create an rsl.out.0000 and rsl.error.0000 file. If successful, the following input files for wrf will be created:
     
         wrfbdy_d01
         wrfinput_d01
     
    Delete or remove the rsl.out.0000 and rsl.error files before continuing as they will be used again.

 

Run wrf

  • Run program wrf for a model simulation and forecast:
     
         mpirun -np 2 -machinefile ~/mach wrf.exe   
     
    Running a 24 hour simulation of this case will take approximately 40 minutes on the classroom machines (so plan on running this in the background). If successful, this will generate the following history file (all times periods will be stored in this file):
     
             wrfout_d01_2005-08-28_00:00:00


 

Check output:

    • Check to see what are printed into rsl.out.* and rsl.error.* files.
    • tail rsl.out.0000 to find "SUCCESS COMPLETE WRF".
    • type the following to see output times available in wrf history file:
       
          ncdump -v Times wrfout_d01_2005-08-28_00:00:00
       
    • Try netcdf data browser 'ncview' to examine your wrf output file
    • Generate graphics with one of the supplied packages.


If this was successful, you can continue to run another case of your choice.