Inline Lightning NO parameter file for CMAQv5.2


Hello everyone,

I have a question how to create lightning NO parameter file for CMAQv5.2.

I was using R and Fortran codes coming with the package of CMAQv5.1 for creating lightning NO parameters. However, I have recently got an error when I was running CMAQv5.2 with inline lightning option. It requires ‘’SLOPE” variable in lightning parameter file which my file doesn’t have. I checked LTNG_DEFN.F file to see what else it requires and I found a couple of variables that I don’t know how to create. Like INTERCEPT etc.

For now, I made a test. I compiled CMAQv.5.2 with LTNG_DEFN.F file from CMAQv5.1. And it worked with old lightning parameter file but I don’t think this is the best way!

CMAQv5.1 and CMAQv5.2 require different variables for inline lightning NO emission as I see in LTNG_DEFN.F. I went through all documentations about lightning NO emissions but I could not see.

Could you please help me to create lightning parameter file for CMAQv5.2? Maybe I missed in the documentations, but I would be grateful if you can redirect me a wiki page that describing how to create new lightning parameter file (with the variables SLOPE, INTERCEPT etc.)?

Thanks in advance for your time and help!



Hi Burak,

The inline lightning NO production schemes are completely different in CMAQv5.2 from CMAQv5.1. In CMAQv5.2, for inline lightning NO production, there are two options. Option 1, directly use hourly lightning flash data from NLDN to generate lightning NO; Option 2, use the linear regression parameters generated with multiple-year flash data and model predicted convective rainfall. And it is Option 2 that the parameters “Slope” and “Intercept” come from. If you want to use option 2, we need to provide you with the parameter file. Our parameter file is generated for the 12 km US1 domain. If you use model domain differ from the 12 km US1, the parameter file needs to be regenerated. Or if your domain is smaller, you can window that file. Please contact me directly, we can deliver the parameter file to you.

Daiwen Kang


Hi Dr. Kang,

Thank you very much. I will get in touch with you.



Hello Dr. Kang @kang.daiwen ,

If I want to use option 1, how do I get the hourly lightning flash data from NLDN to generate lightning NO?

Thanks in anticipation.



Dear Catalyst,
The raw lightning flash observation data used are not available to the public but can be purchased through Vaisala Inc.:
Daiwen is currently out of the country but he will return the last week of May and will be able to provide you more details on the specific dataset that can be utilized with CMAQ and also other options that you may want to consider.

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Thanks, I really appreciate your timely response.