Adding Initial SST Data to the Model

Interpolate the input data onto our model domain (metgrid.exe)

1. namelist.wps

Note: The default namelist.wps does not have the constants_name variable. ADD this to the metgrid section of the namelist. By doing this, the initial SST data will be copied to all other time periods. Typically for real-time cases, only the initial SST is available. By adding the SST in this manner, we are able to take advantage of the extra input field, even though this field is not available for all time periods. This is a good solution, as SST does not change much from day to day.
 
Note: For detailed explanations of these variables, as well as suggestions for best practices, see the Best Practices WPS Namelist page, or Chapter 3 of the WRF User's Guide

start_date = '2016-10-06_00:00:00',
end_date = '2016-10-08_00:00:00',
interval_seconds = 21600,
fg_name = 'FILE'
constants_name = './SST:2016-10-06_00'
 

2. Run metgrid.exe to interpolate the input data on our model domain:

./metgrid.exe

The text below should appear on your screen during run time. Look for "Successful completion of metgrid " at the end of the run, indicating that all when well during the execution. You can also peruse the metgrid.log file for more information, or use it for troubleshooting if anything went wrong.

Processing domain 1 of 1
SST:2016-10-06_00
Processing 2016-10-06_00
FILE
Processing 2016-10-06_06
FILE
Processing 2016-10-06_12
FILE
Processing 2016-10-06_18
FILE
Processing 2016-10-07_00
FILE
Processing 2016-10-07_06
FILE
Processing 2016-10-07_12
FILE
Processing 2016-10-07_18
FILE
Processing 2016-10-08_00
FILE
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!  Successful completion of metgrid.  !
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    This step will create the following files :

met_em.d01.2016-10-06_00:00:00.nc
met_em.d01.2016-10-06_06:00:00.nc
met_em.d01.2016-10-06_12:00:00.nc
met_em.d01.2016-10-06_18:00:00.nc
met_em.d01.2016-10-07_00:00:00.nc
met_em.d01.2016-10-07_06:00:00.nc
met_em.d01.2016-10-07_12:00:00.nc
met_em.d01.2016-10-07_18:00:00.nc
met_em.d01.2016-10-08_00:00:00.nc
 

3. Check the contents of this file:

a. Use the ncdump utility:
    ncdump -h met_em.d01.2016-10-06_00:00:00.nc
b. Use the ncview utility.
c. This file can also be view with any of the supported graphical tools.

Running real.exe and wrf.exe will be exactly the same as for the Single Domain Case. The only difference will be that the model will now make use of the extra information. For this reason, the button at the button of this page will take you back to runnng WRF for the Single Domain Case.

Run WRF