Hi this is CMAQv5.5 repo MECH directory.
I am curious if it is possible to use CB with aero6 in CMAQv5.5
While it is theoretically possible to do so, it would involve making file modifications that require a fairly detailed understanding of the CMAQ aerosol code.
Could you please share your motivation for reverting CMAQv5.5 code back to using aero6? As discussed in the aero7 release notes and the description of science updates linked from them, aero7 incorporates a number of scientific advances for the representation of SOA.
Thank you for answering
CRACMM is made based on ae6, si I can compare CB-ae6 with CRACMM.
If CRACMM2 is made based on aero7, I am happy to use aero7.
Or any other suggestions?
CRACMM, including CRACMM1, is an updated aerosol representation that is chronologically later than both ae6 and ae7. CRACMM introduces several new SOA precursors (furanone, phenol, cresol, etc) that are not available in ae6 nor ae7. In addition, CRACMM changes how monoterpene SOA is represented (emphasizes autoxidation) and does not use pcSOA. Most critically, SOA in CRACMM fully interacts with the radical budget. Specific updates are available in the work of Pye et al. 2023 for CRACMM1 and Skipper et al 2024 for CRACMM2 updates. We dropped the convention of labeling MECHS by GAS_AE#_aq to emphasize that gas and aerosol (and aqueous) chemistry are not fully separable–the types of SOA generated in a mechanism will depend on what precursors are available and how the SOA is parameterized.
CRACMM, ae6, and ae7 do share some commonalities such as ISORROPIA for inorganic nitrate and ammonium. The folder of aerosol code is also technically the same across all mechanisms as different species are activated in different mechanisms. CRACMM could be considered an update of ae7 which is an update of ae6. Since CRACMM1 was built after ae7, I would not consider CRACMM1 to be built on ae6 and CRACMM2 to be built on ae7. Ae6 was deleted in v5.5 to reflect the fact that it is considered deprecated and superseded by later versions of the aerosol treatment. We usually retain one version back in any given release.
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