Hello, I am using CMAQ_ISAM v5.3.3 and have tagged all seven species related to PM2.5. When analyzing the PM2.5 data from the CMAQ-ISAM output, I found an issue: the total concentration of tagged species accounts for only 30–40% of the total PM2.5. In addition, the sectoral source contribution results are also very abnormal and differ greatly from those reported in previous studies in the literature.
Could these abnormal results be related to a low tagging ratio? If not, what other factors might cause such abnormal results? I look forward to your reply.
The issue I encountered is that when calculating the tagged PM2.5 concentration (SA_ACONC), I found that it differs significantly from the values in ACONC. In my calculation(SA_ACONC), I only used:
PM25_TOT [µg/m³] = (ATOTI × PM25AT) + (ATOTJ × PM25AC)
where:
ATOTI = ASO4I + ANO3I + ANH4I + ANAI + ACLI + AECI + AOTHRI + APOCI + APNCOMI
ATOTJ = ASO4J + ANO3J + ANH4J + ANAJ + ACLJ + AECJ + AOTHRJ + AFEJ + ASIJ + ATIJ + ACAJ + AMGJ + AMNJ + AALJ + AKJ + APOCJ + APNCOMJ
These species were included in the calculation because they are all the taggable species related to PM2.5. I would like to ask what might be the possible reasons for this. These are the only species that can be tagged in the file.isamcontrol.txt