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Setting time-varying GHGs with RRTMG physics scheme

This post was from a previous version of the WRF&MPAS-A Support Forum. New replies have been disabled and if you have follow up questions related to this post, then please start a new thread from the forum home page.


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I'm attempting to set time-evolving CO2 in my WRF runs. I've compiled WRF with the added option -DCLWRFGHG which is supposed to enable this yearly GHG function, and I have the RCP8.5 and RCP4.5 files in my directory. My question is, how do I turn this setting "on" in my WRF runs? Is there an option in namelist.input? And how can I specify which RCP file it points to? Will it just go to whichever file is in my run directory? Also, the files specify that it's for the CAM physics scheme, but I read online that you can also have yearly CO2 for RRTMG. Will it work with RRTMG?
Sorry for the slate of questions. Thanks!
This topic has been moved to the WRF Physics section of the forum, as it is more applicable here. Someone will reply to your inquiry soon.
Once you compile WRF with the option -DCLWRFGHG, time-evolving CO2 will be automatically turned on. The only thing you need to do is to link the correct file as CAMtr_volume_mixing_ratio in your working directory. For example, suppose you want to run with the RCP8.5 scenario, then you can type (in your run directory):
ln -sf WRF/run/CAMtr_volume_mixing_ratio.RCP8.5 CAMtr_volume_mixing_ratio

Please try and let me know if you have any problems.
Thank you so much! Is there a way to test to make sure it was actually turned on?
Also, in order to turn it on, do I have to recompile WPS too?
You don't need to recompile WPS. This is a run time option.
This data is read into the model system in phys/module_ra_clWRF_support.F. You can always print something there to check the data.