In one of my cases, I have constant grid emissions. However, in CONC file, the concentrations at the first (bottom) layer don’t show the constant emission. It seems that at 1-4 hour, the highest emission grids do not emit gas. From 5 to 14hour, the emissions start to work. Afterwards, the produced pollutants moved under meteorological conditions, but the emissions stop. I attached the 24 hours concentration profile and the constant emission below. The chemical from CONC file is ACAJ and the chemical from emission file is PCA. I also checked SO2 and NO2, the temporal change is similar to ACAJ.
I checked the dry and wet deposition. They are much smaller than the ambient concentrations. The volume of the grid cell and the air density don’t change much.
What other parameters should I check and how can I understand the unbalance?
Thank you very much for the reply. I use CMAQ v5.2 and do not have EMISDIAG option in CCTM run script. Instead I switch on the process analysis and vertical dispersion diagnostic option. The concentration change caused by emissions is almost equal to the change caused by vertical diffusion in the first layer.
I also attached the change of the boundary layer here. At the beginning, the hot spots of high emission do not have a high boundary layer but show no concentration at first layer. later until the boundary layer gets thicker there seems to have some concentration in the ambient.
It is still confusing. Why emission is removed all by the vertical diffusion immediately? I also want to check the eddy diffusivity but cannot find where they stored.