Misalignment of WRF Grid in Lat-Lon Projection

[Ame]

Hello WRF Community,

I am conducting an air quality simulation over the Himalayas, using WRF for meteorological inputs and integrating emissions from the EDGARv8 inventory into the air quality model. To ensure consistency, I need to define a WRF domain that perfectly matches the EDGARv8 grid. However, I am encountering an issue where the spatial grids of WRF and EDGARv8 do not align correctly.
Here are the key details of my setup:

• WRF Projection: Lat-Lon
• Grid Resolution (dx, dy): 0.1°
• Domain Size: (e_we = 401, e_sn = 351)
• EDGARv8 Emission Grid:Global coverage with a 0.1° resolution and in lat-lon projection.
  • Domain extent: 5°N to 40°N (latitude) and 60°E to 100°E (longitude).
• Issues observed:
  • When overlaying the WRF grid with the EDGARv8 grid, I notice a misalignment of grid cells.
  • The displacement is not systematic, varying from 2 meters to less than 1 millimeter in both longitude and latitude.

Questions:​

1. Has anyone encountered a similar issue when running WPS and WRF?
2. Could this be due to the way WRF interpolates the domain in lat-lon projection? If yes, how exactly does it work?
3. Are there recommended best practices to ensure proper alignment between an external grid and WRF's?

You will find my namelist.wps attached for reference.

Any insights or suggestions would be greatly appreciated!

Thank you in advance for your help!

Best regards

 

[Ming Chen]

For lat-lon projection used in WRF/WPS, I believe that you need to set three parameters:

pole_lat, pole_lon and stand_lon.

Please figure out the corresponding information in your EDGARv8, and set the values accordingly.

 

[Ming Chen]

Please take a look at the document here, which might be helpful for you.