Hi,
I am currently running CMAQv5.4.0.1/HDDM with the chemistry mechanism cb6r5_ae7_aq. My objective is to calculate the sensitivity of VOCs to O3 (ozone). The VOCs included in my analysis are:
AACD, ALD2, FORM, MEOH, FACD, ALDX, ETHA, ETOH, KET, PAR, ACET, PRPA, ETHY, ETH, OLE, IOLE, ISOP, APIN, TERP, BENZENE, TOL, XYLMN, NAPH, and SESQ.
Could you please confirm if I am missing any relevant VOCs for my analysis?
Thank you.
Hi FengLiu,
The importance of individual VOCs is something that you will need to decided on your own in probably depends on your application and goals.
But to clarify, do you plan to calculate sensitivity of VOCs to O3 or the sensitivity of O3 to VOCs? Both are possible, but there are normally no emissions of O3, but it does exist in initial and boundary conditions for use in DDM-3D.
Sergey
Hi Sergey,
I intend to calculate the sensitivity of O3 to total VOCs which should be listed in sensinput.dat. In order to proceed with my CMAQ/DDM3D run using the cb6r5_ae7_aq chemistry mechanism, I have reviewed all 27 VOC species listed in CMAQv5.4/CCTM/node/BLD_CCTM_v54_DDM3D_pgi/SA_DEFN.F, as mentioned in Winston Hao’s message.
However, I have noticed that ECH4 and CO are included in the list, while AACD, FACD, and SESQ are missing. I’m curious about the presence of ECH4 and CO, as well as the absence of AACD, FACD, and SESQ.
VOC defined by SA_DEFN.F
500 !CB6R5_AE7_AQ
501 ALLOCATE( ISAM_SPEC_VOC( 2 )%LIST( 27 ) )
502 ISAM_SPEC_VOC( 2 )%LIST = (/'ALD2 ','ALDX ','ETH ',
503 & 'ETHA ','ETOH ','FORM ','IOLE ','ISOP ',
504 & 'MEOH ','OLE ','PAR ','TERP ','TOL ',
505 & 'XYLMN ','NAPH ','ETHY ','PRPA ','ACET ',
506 & 'KET ','GLY ','BENZENE','GLYD ','MEPX ',
507 & 'APIN ','SOAALK ','ECH4 ','CO '/)
Thanks.
That list is for use in CMAQ ISAM for a specific chemical mechanism. The list was populated manually mainly taking into account ozone production considerations. CO was added because it was important for this purpose. I honestly don’t remember why the others were omitted, and it could be a mistake.
Still, you as a user need to decide on your own what you consider to be a “VOC” for your application.
Sergey
Hi Sergey,
Thank you for your response. I appreciate it. You are correct that the species of volatile organic compound (VOC) components depend on specific chemical mechanisms. Carbon monoxide (CO) is considered an ozone precursor, but it is not classified as a VOC species. Similarly, ethane (ECH4) is also not considered a VOC species.
In a specific chemical mechanism, there should be a predetermined set of VOC species included. However, the ISAM_SPEC_VOC defined in SA_DEFN.F makes me confused.
Thank you.
Honourable Professor.
Hello, I would like to ask a question, I am currently using CMAQ5.4 version, but I have to input the emission list is CB05, because CMAQ5.4 inside the CB6 mechanism does not have XYL but only XYLMN, and now it is currently the state of the report error, I would like to ask for advice on this situation can the CB6 mechanism file inside the XYLMN directly change to XYL?
Please see my response to your question in the other thread on how to use the DESID module to map your CB05 XYL emissions to the CB6 XYLMN and NAPH model species.
Hello, professor, I would like to ask you a question. At present, I process the file after DDM, which is CCTM_SENDDEP_v54_intel_d01_20170202.nc, and the processing result is shown in the file. I find that it only shows the level level is 0 and the contribution of NMVOC to FORM for each grid. Does it not distinguish the effect of emission from grid 1 on grid 2, only the effect of emission from grid 1 on grid 1 can be shown?
FORM_EVC_data.xlsx (4.5 MB)
I am not sure I understand your question completely and I don’t know how to interpret the numbers in the spreadsheet you posted without further context, but here are a few thoughts:
ACONC_BLEV_ELEV (controlling CCTM_ACONC and CCTM_ASENS) and/or CONC_BLEV_ELEV (controlling CCTM_CONC and CCTM_SENGRID) to the desired layer ranges.BCON rather than EMIS sensitivity type in sensinput.dat (see the DDM-3D documentation for further information). However, this will not explicitly track the sensitivity of mixing ratios in an inner domain towards specific emission sources in an outer domain, only towards the cumulative impact of processes occurring on the outer domain that affect the boundary conditions being prepared for the inner domain.Dear Professor, at present, I have invoked DDM calculation to generate two files, whose names are CCTM_ASENS_v54_intel_d01_20170226.nc and CCTM_SENDDEP_v54_intel_d01_20170227.nc, respectively. Because I want to obtain the unit contribution concentration of source concentration to receptor emission, as shown in the article in the screenshot, the last file I extracted should be CCTM_SENDDEP_v54_intel_d01_20170227.nc, right? But I found that it only contains layers of data. Finally, I need to compare it with satellite data. So is it necessary to set up a multi-layer simulation when calculating?
I am not sure how else to explain it, so I’ll essentially repeat my answer from above:
I’m guessing you’re interested in sensitivities of pollutant concentrations (not deposition fluxes) to the specified sensitivity parameters based on the paper you posted (ACP - A new inverse modeling approach for emission sources based on the DDM-3D and 3DVAR techniques: an application to air quality forecasts in the Beijing–Tianjin–Hebei region).
If you are interested in sensitivities of pollutant concentrations to the specified sensitivity parameters, you need to look at the variables in CCTM_ASENS, and if you need 3D information for your analysis, you need to set ACONC_BLEV_ELEV correspondingly. If instead you are interested in sensitivities of pollutant dry/wet deposition fluxes to the specified sensitivity parameters, you need to look at the variables in CCTM_SENDDEP and CCTM_SENWDEP. Since these are fluxes at the surface, the fields are always 2D.
