Request for Guidance on PM2.5 and PM10 Calculation from WRF-Chem Outputs

[Alice Burton]

Dear WRF-Chem Development Team,

I hope this message finds you well.

 I am currently working with the WRF-Chem model for air quality simulations. I would greatly appreciate your guidance regarding the correct method for calculating PM2.5 and PM10 concentrations from WRF-Chem output files.

Specifically, I would like to know:

1. Which aerosol species (e.g., sulfate, nitrate, organic carbon, dust, sea salt) should be included in the calculation of PM2.5 and PM10?

2. Are there any recommended formulas or scripts for summing these components, especially when using chemical mechanisms such as MOZCART or GOCART?

3. What is the correct approach for converting units from µg/kg (if applicable) to µg/m³? Should I compute air density manually, or is there a recommended method within WRF-Chem outputs?

4. If available, is there any official documentation or reference that outlines best practices for this type of post-processing?

Any advice, references, or example scripts would be highly appreciated, as they would greatly help ensure accuracy in the analysis of particulate matter from the model outputs.

Thank you very much in advance for your time and assistance.

Kind regards,

[Mary Barth]

Hello Alice,

WRF-Chem has a module that calculates PM2.5 and PM10. It's called sum_pm_driver which is in aerosol_driver.F. Please use that for guidance, but also look to see if PM2_5_DRY and PM10 are already in your wrfout files. They usually are computed and included in wrfout. They are both in ug/m3. 

- Mary 

^--^--^--^--^--^--^--^--^--^--^--^--^--^--^-^--^--^--^-^--^

Mary Barth 

Senior Scientist   

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

NSF - National Center for Atmospheric Research

P.O. Box 3000

Boulder, CO 80307

Staff web page

SIMA Web Site

MUSICA Web Site

DC3 Web Site 

^--^--^--^--^--^--^--^--^--^--^--^--^--^--^-^--^--^--^-^--^