Would someone please kindly confirm that I have to re-run WRF if I want to add nesting grids to the same study area or reducing the grid size for a CMAQ run of the same time period? I really appreciate that!
Hi nimaaandm,
From your statement “if I want to add nesting grids to the same study area or reducing the grid size”, there are two questions as the following.
1. reducing the grid size
Let say, your original grid size is 36km, now you want to run your model with 12km resolution. You need to rerun everything, i.e. create new 12km resolution WRF input, rerun WRF model, create new 12km resolution CMAQ input, rerun CMAQ.
2. with a nesting grid setup
Let say, you want to have a nesting 3-level setup: outer 108km, middle 36, and inner 12km. For the CMAQ offline model, you need to create WRF input as well as CMAQ input for all those resolutions. It is also true if you want to run with the WRF-CMAQ coupled model. In either the offline or the WRF-CMAQ coupled model, you need to run the model one level at a time. We have developed a new way to run the WRF-CMAQ. In this new way, WRF is running in the normal nested configuration, and WRF only interacts with CMAQ in the most inner level. Currently it is not available to the public and if you are interested in this, please let me know directly (wong.david-c@epa.gov).
Cheers, David
Thank you so much for confirming this, David! I will keep you posted.
Fondly, Nima