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Query on the 'namelist.input' file for running WRF-Chem to study aerosol-cloud-climate interaction


Dear all,
I have some small queries about the setup of some variables in 'namelist.input' file for running WRF-Chem to study aerosol-cloud-climate interaction.
1. After going through various research papers on aerosol-cloud interaction studies using the WRF-Chem model, the user guides, and tutorial presentations available on the WRF-Chem official webpage, I noticed that the cumulus parameterization scheme is not used if the resolution of the domain is 4 km or less than 4 km. Then, if I set the resolution of my d02 as 4 km, should the options 'cu_physics' be set to '0' and 'cu_rad_feedback' be set to 'false' for that domain?
2. I also learned that to study the aerosol indirect effect, the options 'wetscav_onoff' and 'cldchem_onoff' should be set to 1. And it is mentioned in the 'Best Practices for Applying WRF-Chem' tutorial presentation that in the 'chem' section of the namelist, 'conv_tr_aqchem' and 'conv_tr_wetscav' should be set to '1' to include aqueous chemistry and convective wet scavenging. So, what should I set for the options 'chem_conv_tr', 'conv_tr_wetscav', and 'conv_tr_aqchem' for d02 (4 km)? '0' or '1'?
3. I noticed in many online discussions, including the tutorial presentation 'Best Practices for Applying WRF-Chem' available on the WRF-Chem official webpage, that some people used 'emiss_inpt_opt = 102' when considering the MOZART-MOSAIC chemical mechanism. But it is mentioned in the WRF-Chem User's Guide that 'emiss_inpt_opt = 111' for RADM2 emission speciation is adapted after reading the data file to follow the MOZART framework. So, which 'emiss_inpt_opt' is appropriate to use for the MOZART-MOSAIC chemical mechanism? 102 or 111?
Could someone please guide me in this regard? It will be very helpful for me. Thank you for your time and consideration.
With regards,
Hi Ankan,

Yes, 1-4km resolution is generally considered a "gray zone" for cumulus parameterization, meaning that using it can be up to the user. In general, you it will not negatively impact your simulations, though you may want to run a test with and without it, and compare to observations you deep important for your simulations.

As for the addtional settings, 'conv_tr_aqchem' and 'conv_tr_wetscav' are options that control the parameterized aqueous chemistry and convective transport within the cumulus parameterization. So, if you set cu_physics = 0, those two options will not be activated. In general, both should be set = 1.

For your emissions, you need to choose the option that represents your emissions and your simulation. If you are using RADM based emissions in a MOZART simulation, then you need to use emiss_inpt_opt = 111.