# Some questions in CCTM

**URL:** <https://forum.cmascenter.org/t/some-questions-in-cctm/5403>\
**Category:** CMAQ\
**Tags:** cmaq, emissions\
**Created:** [December 2, 2024, 12:45pm UTC](https://forum.cmascenter.org/t/some-questions-in-cctm/5403 "2024-12-02T12:45:50Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Sunchanglei](https://yyz1.discourse-cdn.com/flex027/user_avatar/forum.cmascenter.org/sunchanglei/32/4358_2.png) [@Sunchanglei](https://forum.cmascenter.org/u/Sunchanglei)\
**Post date:** [December 2, 2024, 12:45pm UTC](https://forum.cmascenter.org/t/some-questions-in-cctm/5403/1 "2024-12-02T12:45:50Z")

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Hello everyone,  
I am learning CMAQ, recently in the CCTM input file, and i would like to ask you how to place the MEIC list file.  
I used ISAT to process the MEIC list. Because 36km is used to simulate the whole country, all the data of the five departments are processed as non-point sources. May I ask how to put these files into the CCTM script?  
The picture below is my own random. In the inline section, emisfiles of 5 departments are arranged. Since there is no point source, setenv NPTGRPS 0.  
Please teachers for guidance on how to correctly place several emission sources…And I would like to know whether set STKCASEG and set STKCASEE need to add #?  
The CMAQ version is 5.2.

 ![微信图片_20241202160445](https://canada1.discourse-cdn.com/flex027/uploads/cmas/original/2X/8/8fb27e955fd2454c17ffc3375c9b5ffc45c4b338.png)

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**Author:** ![hogrefe.christian](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@hogrefe.christian](https://forum.cmascenter.org/u/hogrefe.christian)\
**Post date:** [December 2, 2024, 8:33pm UTC](https://forum.cmascenter.org/t/some-questions-in-cctm/5403/2 "2024-12-02T20:33:33Z")

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In CMAQv5.2, you can only use a single gridded emissions file which you specify by setting the EMISfile variable.

If you have multiple gridded emission files, you either need to merge them together (e.g. by using a tool like the SMOKE mrggrid program), or you need to upgrade to a newer version of CMAQ which allows the specification of multiple gridded emission files.