EPA 2016v1 SMOKE ptegu run: What is "ussa" means in the EPA SMOKE output?

Hello,

I am exploring the EPA SMOKE CMAQ ready output for the ptegu sector from here ftp://newftp.epa.gov/air/emismod/2016/v1/postv1_updates/ptegu_2023_2028/ and I can see the SMOKE output file name has "ussa"
for example here : 'inln_mole_ptegu_summer_20160506_12US2_cmaq_cb6_2028fh1_ussa_16j.ncf"

But when I ran SMOKE using same scripts and directory_definition file ftp://newftp.epa.gov/air/emismod/2016/v1/
directory_definitions_12US2.TXT (3.9 KB)
ADEQ_Annual_ptegu_daily_winter_12US1_2028fh1_16j.txt.txt (7.5 KB), my output file name has
no "ussa"

When I am reading the readme https://gaftp.epa.gov/Air/emismod/2016/v1/2016_v1_platform_package_30apr2021.txt , I see a line " the files that CAMx needs are the emis2d file with “+ss” in the name (includes sea salt), and the mrgpt file"

My questions are:

  1. Why the output name is different using the same scripts? Is ussa has any significant meaning in the file name?
  2. Is it something related to sea salt +ss?. If it is, how do I address that in the SMOKE input provided here ftp://newftp.epa.gov/air/emismod/2016/v1/

Thanks in advance

Ussa is short for US source apportionment. It’s possible some files were uploaded from a source apportionment case, but it’s not a problem that your files don’t have ussa in their name.

You’ll want to include sea salt in the low-level emissions you provide to CAMx. The CAMx conversion scripts with the package should help you set that up.

Thank you so much for the response. Your help is greatly appreciated.