How to deactivate ModAero?

#1

Hello, I want to deactivate ModAero, what should I do?
My version is CMAQ5.0.5. Thank you.

#2

There is no CMAQ5.0.5 that was publicly released, so I do not know what it contains and cannot comment as to how it should be modified.
I am not sure what you mean by “deactivate ModAero”. CMAQ used to include a “noop” (no-operation) option for each of its science processes. For example, in CMAQ 4.7.1 one could use the cb05cl mechanism with the aero_noop aerosol module. These “noop” variants were removed for ease of code maintenance, and because it was judged that running the model without aerosols was not scientifically desirable. Depending on what you are trying to do for a research application, you might work with v4.7.1. There were also a few papers using sectional versions of the aerosol model, including CMAQ-UCD and CMAQ-MADRID. Alternatively, the current version of CMAQ could be modified to remove aerosols, but doing so is not simple and is not supported. Having said that, forum users might be able to offer suggestions if you describe more fully what it is you are trying to do.

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#3

Thanks very much for your reply.
I’m very sorry that I wrote the wrong version. My version is CMAQ 5.0.2.
According to your suggestion, I find the “noop” in v4.7.1, and I don’t find the “noop” in v5.0.2. “These “noop” variants were removed for ease of code maintenance.” Does this mean the “noop” is not provided in CMAQv5.0.2 and later?
It’s truly that running the model without aerosols was not scientifically desirable. I want to evaluate the differences between results of opening or closing for some primary pollutants.
My ability may not enough to modify the code now. "Alternatively, the current version of CMAQ could be modified to remove aerosols, but doing so is not simple and is not supported. " Does this mean that it’s not easy to remove aerosols in CMAQv5.0.2 and later? Can you give me some suggestions? Thank you.

#4

Correct. It is not easy to remove aerosols in CMAQv5.0.2 and later.

I do not understand what you mean by “differences between results of opening or closing for some primary pollutants”. But if you mean you want to set some primary pollutant emissions to 0, then that is quite straightforward and does not need any modification to the CMAQ code.

#5

Thank you very much. I’m sorry for my unclear expression.
“differences between results of opening or closing for some primary pollutants” means that I want to know the contribution of aerosols to concentration of primary (e.g. CO) pollutant.