Oligomers of anthropogenic and biogenic SOA (AOLGAJ, AOLGBJ)

Hi, all!

I am studing about secondary organic matter of CMAQ v5.3 AERO7 module.

And I am wondering how oligomer of anthropogenic biogenic SOA (AOLGAJ, AOLGBJ) is formed in AERO7 module.

I referenced species definition txt file (Specdef_cb6r3_ae7aq.def) but I just found that AOLGA and AOLGB can be formed from AAVB2J ~ AAVB4J and AISO1J ~ AISO2J.

So, my question is what is the chemical mechanism of formation of AOLGAJ and AOLGBJ ??
And where I can find the cmaq source code describing about formation of AOLGAJ and AOLGBJ ??

I hope I can get any answer from you all.

Thank you.

HyeonYeong Park

Hello HyeonYeong,

The accumulation mode oligomeric species AOLGAJ and AOLGBJ are formed from the one-way oligomerization of ASOA and BSOA species, as you have pointed out. The rates are specified in the mechanism definition file: lines 460-466.

The rate constants for these conversion reactions are applied in the subroutine HETCHEM_RATES in the AEROSOL_CHEMISTRY.F file. The stoichiometry is applied in the solver you have invoked (e.g. EBI, Rosenbrock, SmvGear).

Best wishes,

Hi, Dr. Murphy!

Thanks to your kind response :slight_smile:

I have checked about oligomerization in CMAQ version 5.3.1 source code you mentioned.

Thank you again :slight_smile:

Best regards,
HyeonYeong Park