Questions about CMAQ 5.3.2 output and emission inventory

I want to ask two questions which I can’t find answer.
1). What’s the difference about ALD2 and ALD2_PRIMARY(ACRO & FORM too) in ACONC file? Is there any docs which I can find the further description for output species?
2). How CMAQ distribute 14-level emission inventory to 35-level model?
Best regards,

Hi Yunqing,

  1. As indicated here: CMAQ/ at master · USEPA/CMAQ · GitHub
    the XXXX_PRIMARY species are only from emissions, not from secondary processing of other precursors.

  2. Do you mean that you have a 14-layer gridded file that you are using in a 35-level model? If that is the case, then it CMAQ will put the emissions into the first 14 layers of the model domain. If the levels of your 14-layer file do not correspond to the first 14 layers of the 35-level grid, I recommend you modify your IOAPI emissions file so that additional layers (equal to 0) are added between your existing layers until your input layer heights are consistent with the 35-layer grid. The emissions module for CMAQ (DESID) can currently only map 1:1 gridded input layers to internal model layers. However, you provide fewer layers than the full number of internal layers (35 in this case). So if your highest layer (number 14) in consistent with internal model layer 25, for example, then you would need an input file with 25 layers.

I am mentioning @hogrefe.christian, @cgnolte, and @barronh in case they have a better recommendation for problem 2.

Best wishes,

1 Like

Hi Ben,

Thank you very much for your answer. It’s very helpful.

Best wishes,