How to calculate PM25_TOT/PM25 Concentration from CMAQv5.3.2-ISAM results?

Dear @sergey @hogrefe.christian,

I have successfully run ISAM using CMAQv5.3.2 with saprc07tic_aero6 mechanism. Please, how do I calculate the concentration of PM25_TOT or PM25 from my results? I don’t know which species definition to be used as this is different from the normal CMAQ calculation.

Thanks in anticipation and kind regards.

As noted by @ykaore in posts 3 and 9 of the other thread that question came up, you’ll have to work with the Aitken and accumulation mode species provided by your ISAM run.

Simply put, sum up all the PM species provided in your ISAM output file and multiply the Aitken mode species with PM25AT and the accumulation mode species with PM25AC. Post 9 contains an example how this was done in @ykaore’s case. Note that this will be different from the standard PM25 calculation using the concentration output files because coarse mode species aren’t included in ISAM. @sergey may have additional thoughts.

Additionally @Catalyst2682, you can also compare the PM25_TOT from ACONC or COMBINE files and the values that you are gonna calculate using ISAM output in order to have a look if the differences are inegligible or not (in this case, to have look at the influence of coarse mode in your PM25_TOT).


Thanks for your response. I’ll follow @ykaore’s method as I’ve been in contact with her on this. I only want to know if there’s an alternative to it.



Yes, I’ll do and compare the results as suggested by you. I’ll feed you back.

Thanks and kind regards,