CMIP5/CMIP6 initial and boundary condition for WRF

[sium]

Hello,

I am new to initializing WRF using CMIP data. Can someone list the steps on how to generate metgrid data from CMIP and Vtable i should be using


Thanks

 

[kwerner]

Hi,
If you do a search in this forum for "CMIP" you can see a few other conversations that have taken place regarding CMIP data, and that may be helpful to you. You will need to obtain data containing the mandatory variables for running WRF. As for a Vtable, I would advise to use an existing Vtable and make modifications to use the GRIB codes used for CMIP data, assuming the data are in GRIB format. You can use the program /WPS/util/g2print.exe (or g1print.exe) to see the variables listed and their codes.

 

[sium]

Hello Kwerner,

I read running ungrib is not need when you initial WRF with CMIP data. Just start CMIP model output to create intermidate data (met_em_d0?) . That is why I am asking for the step to follow on how to initialize WRF with CMIP.

 

[kwerner]

If the CMIP output is already in intermediate format, then you can just run geogrid.exe and then metgrid.exe, using the intermediate files. If the output is in another format (e.g., netCDF), then you'll need to convert it to intermediate format first. You can read more about that process in chapter 3 of our Users' Guide. There are also a couple of scripts others have shared with us for converting from netCDF format to intermediate format. You can find those here. Just keep in mind that they were created by outside sources for their specific application. You will need to modify them for your data. We also do not support those scripts since we did not write them. They may be outdated and you may need to do a bit of research to update them if you run into trouble. There may also be other scripts available elsewhere, or perhaps in this forum (you could try using the search tool). Once you convert the data, you'll just run geogrid.exe and metgrid.exe, and if those are successful, you'll continue to run real and wrf.

 

[dileepkunjaai]

I am also facing the same issue. I created CMIP6 intermediate files, but how to set those files path in namelist.wps for running metgrid.exe [I can copy those files into em_real directory, but there are a large number of files, so if I can handle it in a separate directory it will easy.

 

[kwerner]

I am also facing the same issue. I created CMIP6 intermediate files, but how to set those files path in namelist.wps for running metgrid.exe [I can copy those files into em_real directory, but there are a large number of files, so if I can handle it in a separate directory it will easy.

If you've put your intermediate files in a location other than your WPS directory, you can use the namelist.wps parameter "fg_name" to show not only the prefix name, but also a path to those files. For e.g., if your files had the prefix "CMIP6" and you had them in a directory /home/user/int_files, you could set

fg_name = '/home/user/int_files/CMIP6'

and then metgrid would look for the files in that directory, instead of in the WPS directory.