# Double counting NH3 emissions when using NH3 Bidi flux in CMAQ

**URL:** <https://forum.cmascenter.org/t/double-counting-nh3-emissions-when-using-nh3-bidi-flux-in-cmaq/1861>\
**Category:** CMAQ-PREP\
**Tags:** smoke\
**Created:** [October 23, 2020, 5:55pm UTC](https://forum.cmascenter.org/t/double-counting-nh3-emissions-when-using-nh3-bidi-flux-in-cmaq/1861 "2020-10-23T17:55:04Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![skunwar](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@skunwar](https://forum.cmascenter.org/u/skunwar)\
**Post date:** [December 7, 2020, 3:09pm UTC](https://forum.cmascenter.org/t/double-counting-nh3-emissions-when-using-nh3-bidi-flux-in-cmaq/1861/5 "2020-12-07T15:09:18Z")

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Thanks a lot for the information.

I searched for the terms DepMod, stage and m3dry in my CMAQv5.3.2 (cb6r3\_ae7) runscript, and did not find any of them. Then I check my CMAQ BLD\* directory when I saw m3dry.F and m3dry.o files, which confirm that I am indeed running the m3dry module.

Actually, my CMAQ run has not aborted at these **NaN** values of NH3 and NH3\_Emis in the CCTM\_DEPV\_\* CMAQ output files, or the **Infinity** values of standard deviation (screenshot shown in the post [NaN values of NH3\_Emis variable in CCTM\_DRYDEP\_\* file](https://forum.cmascenter.org/t/nan-values-of-nh3-emis-variable-in-cctm-drydep-file/1964)) of all FEST model output files (input to CMAQ bidi).

My questions here:

1. Is it a possibly a problem starting with the FEST input files that I downloaded from the repository?
2. Is there any preference between the two modules m3dry and stage for NH3-bidi process? Would using stage have avoided getting NaN values for NH3 and NH3\_Emis variable in CCTM\_DEPV\_\* files?

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