Overlapping domains

[icastorm]

I am currently designing an OSSE using a single domain convection-allowing nature run and single domain control runs at the same resolution. The only difference is in the location and size of the domains - the nature domain occupies a much larger area. For ease of verification, I'd like to overlap the two domains, such that they share grid point locations where the domains overlap, as if they were nested. The problem with this is that the ref_lat/ref_lon values are going to need to be different, and due to a lack of precision I can't get the nature and control domains to line up perfectly.

I have thought that perhaps a "fake" geo_em.d02 file can be produced initially, nested within the nature domain and then carried forward as d01 for the control runs, but then WRF also requires the ref_lat and ref_lon values to be set, which would seem to defeat the purpose of using the nested domain at all.

What is the correct procedure for producing two overlapping domains without nesting them?

Thanks!

Isaac

 

[kwerner]

Hi Isaac,
I wonder if you could set it up, initially, in your namelist.wps file, so that the parent_grid_ratio is simply 1:1. You would need the larger domain to be set up as d01. I just ran a test with geogrid and it didn't complain, but I've not tested this all the way through the wrf.exe process. I'm not sure if this will help you achieve the results you want, but I thought you may want to try playing around with that option.