Dear Professor, I would like to ask a question related to DDM simulation, I would like to simulate the DDM sensitivity results of the sum of anthropogenic VOC emissions plus MEGAN-estimated BVOC emissions to formaldehyde, and now the anthropogenic emissions and vegetation BVOC are labeled as GRIDDED_EMIS and GRIDDED_RWC, respectively.Then, I only write the name of EMIS as GRIDDED_EMIS inside the sensinput.dat, and the final FORM_EVC is only calculating the sensitivity results of anthropogenic VOC to formaldehyde? So, in sensinput.dat, I only write GRIDDED_EMIS in the EMIS name, and the final FORM_EVC is the result of calculating the sensitivity of anthropogenic VOC to formaldehyde only? If I want to calculate the total sensitivity of formaldehyde from anthropogenic plus vegetation sources, how should I write sensinput.dat? Thanks a million again Prof.
@sergey Dear Professor, can you take a look at this for me sometime?
If you want to calculate sensitivity to “FORM” from a defined emissions stream, you would it up something like this:
EFH
EMIS
GRIDDED_EMIS
SPECIES
FORM
END
If you want to calculate sensitivity to “FORM” in two different files independently, it would be:
EF1
EMIS
GRIDDED_EMIS
SPECIES
FORM
EF2
EMIS
GRIDDED_RWC
SPECIES
FORM
END
If you want to calculate sensitivity to “FORM” from 2 emissions streams together it would be:
EFH
EMIS
GRIDDED_EMIS, GRIDDED_RWC
SPECIES
FORM
END
You need to pay attention to line formatting and spaces. All of this is described in the sampled sensinput.dat files and the documentation accompanying the model release.
I don’t really understand the rest of what you are asking.
Sergey
Dear professor, hello. Thank you very much for taking the time to answer your questions in your busy schedule. I should be the last situation you mentioned. I would like to label the sensitivity results of the total emissions of two emission sources (FORM, ETHA, PAR, ETH, OLE, IOLE, ISOP, TERP, MEOH, ETOH, ALD2, ALDX, XYLMN, NAPH) to FORM. I have made the revisions according to your guidance now. Could you help me check again whether the annotations are correct? Thank you again, Professor. Wish you all the best。
I think, in this case, terminology is very important. CMAQ-DDM-3D calculates sensitivity OF all model species (including formaldehyde) TO a pre-defined subset of species from a subset of emissions streams.
In your latest example, you would get in your output the sensitivity OF formaldehyde (and OF everything else) TO the list that includes FORM, ETHA, PAR, ETHA, OLE, IOLE, ISOP, TERP, MEOH, ETOH, ALD2, TOL, XYLMN, and NAPH included in both of the streams in the first paramter; and then the sensitivity OF formaldehyde (and OF everything else) to the GRIDDED_EMIS emissions of NOx in the second parameter.
But in your question, you ask about “sensitivity results OF total emissions” TO formaldehyde. So, try to define what you are trying to do, and the setup will follow more easily.
Also, you still need to pay attention to line formatting and spacing.
Sergey
@sergey Dear Professor, I have a follow-up question regarding DDM simulation results. Since DDM provides sensitivity outputs for individual grid cells (e.g., Grid A shows a sensitivity value of 40 µg/m³), does this result already account for the contributions from emissions in surrounding grid cells that influence Grid A’s concentration? In other words, is the sensitivity of Grid A inherently affected by transport from neighboring grids, or does it only reflect local emission impacts?
The sensitivity output at any time and space (gridcell) is impacted by all model processes interacting with the defined parameter in your input file including transport. If you are still calculating sensitivity to emissions of species in a gridded emissions stream (for example, your GRIDDED_EMIS and/or GRIDDED_BIOG), then any cell in your domain will be impacted to some extent by emissions in all of the emitted gridcells in that stream up to the point in time where you looking at the output.
Sergey