General question about stack_groups and inline files

Hi all!

I have a question about SMOKE outputs for point sources.
I know that there are two different outputs for point sources in SMOKE; stack_groups and inline files. I’m a bit confused since I’m not sure about the difference between these two kinds of outputs. The locations and details about the stacks (such as stack height, diameter, emission rate, and …) are stored in stack_groups files. So do inline outputs only include plume rise?

By the way, if it’s correct, is this why there is only one stack_groups for point sources but one per day stack_groups for fire sectors (each fire event is considered a stack)?

Thank you,

HI Soroush,

Stack_groups files include information on individual stacks – locations and stack parameters – but not emissions information. The inline files include the hourly emissions for
the same sources. The inline files don’t have any specific information about plume rise; they just contain hourly emissions by source. CMAQ uses the stack information from stack_groups + the hourly emissions from the inline files to calculate plume rise.

Non-fire point sectors have a single stack_groups file for the year because each day of the year has emissions from the same group of sources (i.e. the entire inventory). Fire
sectors have day-specific stack_groups files because SMOKE only outputs emissions for fires that are active on any particular day. In other words, each day of the year has a different list of sources for fire sectors (only those fires which are active on that
day), whereas for a non-fire sector, each day of the year has the same list of sources.

We hope that helps…

Along with @eyth.alison information, those list of point sources in stack groups and inline emissions files are considered as elevated point sources that potentially emit emissions into above the surface layer and transport a longer distance in downwind. Not all point sources are considered as elevated but selected by Elevpoint program in SMOKE based on the user’s input.

Hi @eyth.alison @bbaek,
Thank you very much for the helpful information.


When we run CMAQ, we use scripts that use the representative dates files - the same representative date files that we use in SMOKE.

These representative date files are included in most packages in the “SMOKE core” package, and are usually exported to the smoke[version]/scripts/smk_dates/[year]/ directory.

So you can send CMAQ inln files with different dates to account for the representative dates that occur in some sectors…