Hi all,
I’m using CMAQv5.4 now. And I notice that the aerosol part of the CMAQ output file only contains the sum of ANO3-, ASO42- and other inorganic salts. Is there a way to get the concentration of specific aerosol species such as NH4NO3 from ANH4+ or ANO3- variables?
Thanks for your help.
Liu
Hi Fortuna,
CMAQ uses ISORROPIAII to calculate inorganic aerosol (including NH4+ and NO3-) formation. You can see the system of equations in Table 2 of Fountoukis and Nenes 2007 which highlights the connected system. The aqueous NH4+ could be associated with sulfate, bisulfate, or Cl- in addition to nitrate. If you had the form of sulfate vs bisulfate and all other inorganic constituents, you could do a charge balance on fine mode aerosol to get the ammonium specifically associated with nitrate. Bisulfate would have to be saved out. Alternatively, you may be able to back calculated things from pH (or AH3OP).
Havala
1 Like