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.
Could you, please, provide more details on what you are trying to do? ISAM is generally very good at mass conservation compared to bulk values. For example, what do you mean by “all seven species related to PM2.5?” There are a lot more than just 7 species that comprise PM2.5. What does your ISAM control file look like? What are you tracking and what do you mean by “low tagging ratio?”
Sorry for replying so late. 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:
These species were included in the calculation because they are all the taggable species related to PM2.5. However, the tagging ratio is only about 40%. I would like to ask what might be the possible reasons for this. The version I am using is CMAQ v5.3.3. These are the only species that can be tagged in the isamcontrol.txt file.