Is deposition rate of ammonium nitrate (NH4NO3) calculated by CMAQ?


I want to look at deposition rates of ammonium nitrate (NH4NO3). I checked DRYDEP and WETDEP files and I could not find it in those files.

Is the deposition rates of this species included in CMAQ output files, or I have to calculate/estimate it?


Hi Ehsan,

You likely need to use the post-processing tool called combine that is provided with CMAQ.
Use combine to “combine species from raw CMAQ output files or wrfout input files into a new IOAPI output file. Species can be aggregated or transformed into variables of interest”


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Thank you, Liz, for your response. I was looking at spec_def file in the following link and I could not find the NH4NO3 name there. I am not sure if I am looking at the right spec_def file. Can you please advise or point me to the formula for calculating NH4NO3?

Also, I was wondering why NH4NO3 is not calculated as an independent species in deposition module?