About SOA species in CMAQ v5.3

Hi, all,

I’m trying to calculate simulated POA and SOA concentration resulted from CMAQ version 5.3 using AERO7 mechanism.

But I’m confusing whether ‘ALVOO1, ALVOO2, ASVOO1, ASVOO2, ASVOO3’ should be treated as SOA or not since they are oxidation product of POA species and defined as POA in ‘AE_cb6r3_ae7_aq.nml’ file but also Murphy et al. (2017).

However, there is ‘SpecDef’ file representing the calculation of ‘ASOMI’, ‘ASOMJ’ including those oxidation product of POA.

Thus, my question is those oxidation product of POA species should be treated as POA?? or SOA??

I hope I can get any answer as soon as possible.

Thank you.

HyeonYeong Park

Hi HyeonYeong,

Typically we assume that the species you listed are treated as SOA since they are oxygenated and would presumably be detected by an AMS as OOA and lumped with the SOA mass in an analysis like that.

However, it is an ongoing debate whether or not to treat oxidized POA as SOA or not. If you like, you can try both ways to see what makes sense with the measurements you are comparing to. My default would be to assume they are SOA though.

Best wishes,

1 Like

Dear Dr. Murphy

Thanks to your kind response! :slight_smile:
It really helped to understand CMAQ SOA species well.

Thank you again :slight_smile:

Best regards,
HyeonYeong Park