CMAQv5.2 with AERO7 and inline biogenic emissions

Hi all,

I am trying to run a simulation using CMAQv5.2 with input from the 2016V2 platform. The 2016V2 platform is developed using the AERO7 module, whereas the version of CMAQ I am using processes emissions using AERO6. This is an issue, as ~30% of monoterpene will not be accounted for in CMAQ according the AERO7 release notes. The AERO7 release notes include options for adapting AERO6 emissions to be used in a version of CMAQ using AERO7.

I am curious if I can adapt AERO7 emissions to be used in a version of CMAQ that uses AERO6. In my current set up, I use inline biogenic emissions if there is a way to map to the AERO7 to AERO6 in the biogenic speciation file.

Thank you in advance.

Please consider using CMAQv5.4+, rather than modifying CMAQv5.2.
CMAQv5.2 was released in 2017.

There are tutorials available to help you verify that the CMAQv5.4+ version is installed correctly on your system.

Additional information about chemical mechanisms available in CMAQv5.4

I second @lizadams’ recommendation to consider moving to a newer version of CMAQ.

That said, if you are using CMAQ to calculate biogenic emissions inline rather than reading in offline pre-speciated biogenic emissions, you need not worry about the 2016V2 platform being developed for AERO7 rather than AERO6. The B10C6 speciation profile contained in CMAQv5.2 gspro_biogenics_1mar2017.txt and referenced in the CMAQv5.2 example run script (by setting BIOG_SPRO to B10C6) adds BEIS APIN emissions to the CMAQ TERP model species, along with the BEIS TERP emissions. Therefore, you are not missing any BVOC emission mass estimated by BEIS in your simulations as long as you’re referencing the inline biogenic files distributed with CMAQv5.2.

What you will be missing by using CMAQv5.2 and AE6 (i.e. by combining the BEIS APIN and TERP emissions into the same CMAQ TERP species) is the fact discussed in the CMAQv5.3 release notes you referenced that you cannot avoid making SOA from α‑pinene + nitrate radical reactions despite that pathway having been shown to produce negligible SOA. In other words, you’ll be overestimating the SOA from that pathway by using an older version of CMAQ.