Question about vertical levels for air pollution dispersion modeling over the Alps

[Alice Burton]

Dear all,

I am planning to study air pollutant dispersion over a mountainous region in the Alps using WRF/WRF-Chem or a coupled meteorology air-quality modeling setup.

Since the study area has complex terrain and strong near-surface gradients, I would like to ask for your advice regarding the vertical resolution. In particular, I am interested in the appropriate number of eta levels for this type of application.

My main question is about the lowest part of the atmosphere, especially the first 1 km above ground level, where most of the pollutants are expected to accumulate and where boundary-layer processes are very important.

Would it be reasonable to use around 10 vertical levels below 1 km AGL for an air pollution dispersion study over complex mountainous terrain? Or would you recommend using more levels in this layer?

I would also appreciate any suggestions on how to define the eta levels in WRF so that approximately 10 levels are placed below 1 km AGL while keeping a smooth vertical stretching above that height.

More specifically, I would like to know:

1. How many total vertical eta levels would you recommend for a mountainous air pollution dispersion study over the Alps?
2. How many levels should ideally be placed below 1 km AGL?
3. Is 10 levels below 1 km AGL sufficient, or should I consider a finer near-surface vertical resolution?
4. Are there any recommended values or examples for eta_levels in the WRF namelist for this type of application?

Any guidance, experience, or references would be greatly appreciated.

Best regards,

[Mary Barth]

Alice,

I suggest posting this question on the WRF forum where hopefully you will get advice from those who have done similar case studies.

- Mary

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Mary Barth 

Senior Scientist, NSF National Center for Atmospheric Research   

phone: 303-497-8186    email: bar...@ucar.edu

NSF NCAR Staff web page       MUSICA Web Site  

International Commission on Atmospheric Chemistry and Global Pollution

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[Alice Burton]

Dear Mary,

I posted my question where you suggested, however no one replied to me. Could you please help me with your expertise?

Thanks in advance.

Kind regards,

[Will H]

I'll take a stab at this Mary.  Alice can you post your link to the wrf forum post I'll respond there

To unsubscribe from this group and stop receiving emails from it, send an email to wrf-chem+u...@ucar.edu.

[Mary Barth]

Sorry. I'm not an expert at simulations in mountain valleys. Another step is to look for papers doing similar modeling and see what they did.

- Mary

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Mary Barth 

Senior Scientist, NSF National Center for Atmospheric Research   

phone: 303-497-8186    email: bar...@ucar.edu

NSF NCAR Staff web page       MUSICA Web Site  

International Commission on Atmospheric Chemistry and Global Pollution

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