# How to run the local case using wrf-cmaq two-way coupled model

**URL:** <https://forum.cmascenter.org/t/how-to-run-the-local-case-using-wrf-cmaq-two-way-coupled-model/6048>\
**Category:** WRF-CMAQ\
**Created:** [November 7, 2025, 7:05am UTC](https://forum.cmascenter.org/t/how-to-run-the-local-case-using-wrf-cmaq-two-way-coupled-model/6048 "2025-11-07T07:05:46Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![sher](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@sher](https://forum.cmascenter.org/u/sher)\
**Post date:** [November 7, 2025, 7:05am UTC](https://forum.cmascenter.org/t/how-to-run-the-local-case-using-wrf-cmaq-two-way-coupled-model/6048/1 "2025-11-07T07:05:46Z")

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Hello everyone, could you please tell me how to run a local case using the WRF-CMAQ two-way coupled model? What data needs to be prepared in advance? Do I only need to modify the `run_cctm_Bench_2018_12NE3.WRFCMAQ.csh` script? What are the differences between running a local case with the two-way coupled model and the offline coupled model? I’ve successfully run the test case. Additionally, I noticed that the WPS preprocessing module is not included. Does this mean I need to run it in advance to generate the files, and then input them into the WRF-CMAQ two-way coupled model?

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**Author:** ![wong.david-c](https://avatars.discourse-cdn.com/v4/letter/w/bcef8e/32.png) [@wong.david-c](https://forum.cmascenter.org/u/wong.david-c)\
**Post date:** [November 13, 2025, 6:38pm UTC](https://forum.cmascenter.org/t/how-to-run-the-local-case-using-wrf-cmaq-two-way-coupled-model/6048/2 "2025-11-13T18:38:57Z")

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Hi Sher,

WRF-CMAQ coupled model requires the same input as running the CMAQ offline model except the meteorology. WRF-CMAQ provides that directly to CMAQ and offline CMAQ gets it from MCIP which process wrfout files. WRF-CMAQ coupled model has the aerosol radiative direct effect and this makes it more a realistic model than offline model.

In your case, you want to setup all the input for your particular domain, you need to prepare all CMAQ required inputs. On the WRF side, you are right that you need to run WPS as the first time to create all wrf model input files.

Cheers, David

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**Author:** ![Ether](https://avatars.discourse-cdn.com/v4/letter/e/e8c25b/32.png) [@Ether](https://forum.cmascenter.org/u/Ether)\
**Post date:** [November 20, 2025, 9:43am UTC](https://forum.cmascenter.org/t/how-to-run-the-local-case-using-wrf-cmaq-two-way-coupled-model/6048/3 "2025-11-20T09:43:41Z")

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Hi Sher,

I noticed that you creat the same topic both in CMAQ categorie and WRF-CMAQ categorie. For convenience, I only reply you in this topic.

If you have run the offline coupled model, you may know the process for running this program. Use WPS to creat input files for WRF model. Then run the WRF model to make `wrfout*` files. Put the `wrfout`_`*`_ files into MCIP and then make ICON and BCON. You could do the same jobs in the two-way coupled model, just useing run\_cctm.WRFCMAQ.csh instead of run\_cctm\_base.csh. And then run the real.exe again for the two-way coupled. At last ,run the run\_cctm.WRFCMAQ.csh.

As a result you should run the WPS and MCIP.

Generally speaking, two-way coupled model could help you know the climate effect of air pollution while the offline model just tell you the distribution of pollutants.

If you have any other question, feel free to contact me.

Cheers,

Xu