How to avoid zero value of SOA concentrations


I’m trying to interface the new SOA model in CAMx and CMAQ.

When I compare the SOA conc. from the new SOA model with the SOA conc. from the pre-existing SOA model (SOAP2.2 in CAMx),
The minimum SOA concentrations are very different.
The pre-existing SOA model showed at least 0.13 micrograms/m3 of total SOA, but my SOA model showed ‘zero’ conc. sometimes (especially in very little emission area).

This new model is based on chamber simulations, and I want to use it in the regional scale simulations.

Is there some part of skills or tuning to calculate the minimum concentration in the SOA model code?
Should I consider some kind of lower boundary to avoid the ‘zero’ concentration?

Many thanks in advance!

Hi Yujin,

Can you provide more detail about the new SOA model you are referring to, and how it differs from the SOA model currently implemented in the latest version of CMAQ?

When you say that the minimum concentrations from the SOA model are lower, is this prior to implementation in CAMx or CMAQ, or after implementation?

If you are referring to your results after implementation of a new SOA model within CMAQ, please specify the version of CMAQ, chemical mechanism and aerosol module you started with.