OC and SOA calculation in CAM4-Chem

[Hemraj]

Hi,
I am simulating my atmosphere using CAM4-Chem, and I found OC and SOA (kg/kg) in the model output. Is SOA a subset of OC or they are completely different? How are they calculated in CAM4-Chem?

I am wondering do I need to add them separately or I just take OC (ignore SOA assuming it as a subset of OC) to find the total aerosol. Looking for kind suggestions/thoughts.

Many thanks.

Hemraj

 

[Hemraj]

To the best of my knowledge, OC in CAM4-Chem should refer to POC (primary organic carbon), and SOA is Secondary organic carbon, which means they are completely independent (no overlapping). But, to support this OC as POC, I didn't find any documentation so not confident.

Thanks!!

 

[rrbuchholz]

Hi Hemraj,
Modeled aerosols are not my area of expertise, but have you looked into these two articles:
https://doi.org/10.1029/2019MS001827
Characterization of organic aerosol across the global remote troposphere: a comparison of ATom measurements and global chemistry models
Best,
Rebecca

 

[rrbuchholz]

Additionally, this section (6.2.1.5) of the scientific guide talks about SOA being created from VOC oxidation:
6. Extensions to CAM — camdoc documentation

 

[Hemraj]

Dear @rrbuchholz
Thank you so much for sharing the study materials.