EXERCISE 4

Exercise 4: Using mozbc and MOZART GCM data for initial and lateral boundary conditions for the Southeastern Asia domain

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Purpose: To familiarize the user with the use of GCM Data for LCBs in a WRF-Chem simulation.

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  1. Save the wrf output data file from exercise 3 by moving it to a file with a different name. You will need these files to compare the results with the simulation produced later in this exercise.

    mv wrfout_d01_2012-09-14_00:00:00 wrfout_d01_2012-09-14_save


  2. Save the wrf input and boundar data files from exercise 3 by copying them to a file with a different name. You will save these files as the next steps overwrite the chemistry data.

    cp wrfinput_d01 wrfinput_d01_save

    cp wrfbdy_d01 wrfinbdy_d01_save


  3. Obtain the mozbc utility as well as the MOZART model data.

    cd /home/${USER}
    cp -R /CODE/MOZBC MOZBC


  4. The mozbc utility should already be compiled and you should see an executable as well as the input file in the MOZBC directory. Go ahead and move into the MOZBC directory.


  5. Untar the MACC MOZART GCM data from the tar file in /DATA

    tar -xf /DATA/macc_asia.tar


  6. Set the values in the the mozbc input data file. Take care to choose the correct chemistry for the simulation. In this case, it is suggested you use the RADM2SORGAM.mod.inp file.

    A common error when running mozbc is to not have all dates in the MOZART file. Confirm the dates in the MOZART data file using the command:

    ncdump -v date,datesec

    It is recommend that one rename the MOZART netCDF data file from the tar file to remove the date and time stamp. A simple name is prefered; something like h0001.nc. For this exercise, rename all 10 files starting with data for 20150915 being named h0000.nc and incrementing upward the date and file number. You should have in the end 10 different data files named h0000.nc, h0001.nc, h0002.nc, etc.


  7. Run mozbc to modify the wrfinput_d01 and wrfbdy_d01 data files. The program will modify the files to provide the initial state and lateral boundary chemistry data using the MOZART GCM model output.

    If you get an error message when running mozbc, it could be due to some of the chemical species being requested are not included in the MOZART data file. For example, OH could be requested by the program, but not in the MOZART data. This would be due to OH being a short lived species and best computed during the model run. So IF (big IF as it may not happen) one gets an error regarding OH, then just remove OH from the RADM2_SORGAM.inp file speciation list and reruns the mozbc program. The same would work for other short-lived species as well.


  8. Verify that the new intial chemical state and lateral boundary conditions has been changed and includes the MOZART data. For example, look at surface ozone. Do you see an increase in ozone concentration? Does the range relfect a more realistic atmospheric profile? *** Notice that the total range is different that what is used in the figures. ***


  9. Run wrf.exe using the new intial chemical state and lateral boundary conditions. These two new features will require that you set two values in the namelist.input file.

    chem_in_opt = 1

    have_bcs_chem = .true.

    Examine the model results and compare the wrfout file with the wrfout file saved earlier in the exercise.



This concludes WRF-Chem Southeastern Asia domain tutorial exercise 4




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