CMAQv5.5 cracmmv2 Sulfate Species

CMAQ Chemistry and Aerosols
1

Hello,

I am running a cracmm2 simulation using CMAQv5.5 and I had a clarifying question about the sulfate species included in the SpecDef files. Using my model, I am interested in outputting the total aerosol sulfate concentration. From what I understand, ASO4IJ and ASO4K correspond to fine and coarse particulate matter sulfate ions. Do these species represent sulfate from both wet and dry aerosols? In other words, does ASO4IJ+ASO4K account for sulfate present in both aqueous-phase species (H2SO4, HSO4, SO4) and solid-phase species (NH4HSO4(s), (NH4)2SO4(s), etc)? Additionally, is there a way to output the concentrations of individual sulfate species? Any help is appreciated. Thanks!

2

ASO4IJ and ASO4K are the total sulfate in all forms (H2SO4, HSO4, SO4, CaSO4, etc–all the forms ISORROPIAII includes). You could estimate some forms easily (e.g., I recall CaSO4 was one of the first species ISORROPIA will form so you can calculate that by charge balance). HSO4 and SO4 are likely both abundant. You could run ISORROPIAII in box model on output to get the forms. Or CMAQ could be modified to output more information.

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