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Nested domain boundary errors when running an aux input

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Hi all,

I am trying to run a one-way nested LES simulation in WRF-fire using an auxiliary input file to bring in terrain data. In order to properly simulate turbulence in the inner domain, I first "spin up" the outer domain (which is flat) using periodic conditions. I then introduce the nested domain (with auxiliary terrain) after a few iterations with feedback turned off... so the outer domain (flat) feeds the inner domain (w/terrain) without re-introducing terrain wakes back into the outer domain.

When I attempt to restart the model and introduce the inner domain (using an auxiliary input with my terrain data ), the model reads in the terrain correctly, however, after a few iterations, the u, v, and w winds are absurdly extreme around the edges of the inner most domain (see attached screenshots). Additionally, a grid-like feature shows up over the terrain in the "w" field at the lowest model level (see attached screenshot) which I've never seen before.

Therefore, it does not appear that the model likes my auxiliary terrain input for the inner most domain. In fact, when I run the 2 domains simultaneously, and WITHOUT the auxiliary terrain file (i.e. no terrain in either domains), the simulation works fine. I have realistic winds at the boundaries of my inner domain.

My mountain height is roughly 250 m, and the steepest slope is only 10 degrees, so I don't believe the terrain itself is causing the issue. I've also placed the terrain roughly 3 km away from the edge of the inner most domain. My inner most domain is also positioned 5-7 km away from any of the outer domain's boundaries (not sure if that matters).

Does anyone have any ideas on why this may be happening? I'm guessing, I'm not properly utilizing the auxiliary input feature correctly, especially considering that the simulation works fine if I don't use any terrain in either domain and run them simultaneously.

I'm attaching my namelist.input for the restart run which includes the input of the inner domain with terrain. I use the aux7 input, and I call upon a netcdf file called "surface_d02" which houses my terrain I'm trying to bring in. Again, the model recognizes my terrain correctly in the HGT variable, so does appear to read the terrain in correctly at least.

I'm attempting to run this on WRFV4.1.1

Any help or ideas would be greatly appreciated!

Thank you,

u_wind_lowest_level.pngw_wind_lowest_level.pngView attachment namelist.input_step_2.txt
WRF-Fire is handled by some colleagues outside of our group. I've contacted their group and asked them to take a look at this question. Hopefully you will receive a reply soon. Thank you for your patience.