WRFDA for nested domains

[jorge_p]

Hi,
I've been searching the forum and documentation but still no luck for a more detailed explanation of running 4dvar for both the parent and nested domains of a WRF forecast simulation setup.

It's clear that no nesting is supported in WRFDA and one must separately run 4dvar for each domain.

After running real.exe for a 2 way nested run you get the wrfbdy_d01 boundary file only for the parent domain, needed for the assimilation together with wrfinput_d01.
1. How do we continue with the nested domains? Which boundary conditions file wrfbdy_d0? do we use for the nested domains.
Are the namelist.input options grid_id, parent_id, i&j_parent_start relevant when assimilating data over the nested domains?
2. Do we have to use ndown to provide wrfbdy_d02, d03, etc. ?
3. Do we have to run WPS and WRF in single domain mode for each domain (parent and child domains)?


Any help will be appreciated,
Thanks

[JakeLiu]

You are right that WRFDA does not support nested run and you have to run WRFDA separately for different domains.
So for 4DVAR, you need to create a wrfbdy file for each domain you want to analyze.

[zamba666]

had similar issue and yes wrfbdy file helped