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Error with the Urban Canopy Model

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New member
Hi all,
I am facing two problems with the urban canopy model while using WRF-Chem v3.9.1.1 using the ndown approach.
1. When I run the d02, I get the following error, ZDC + Z0C + 2m is larger than the 1st WRF level Stop in subroutine urban - change ZDC and Z0C. Similar errors have been posted in the forum in the past and I have tried both solutions, which are to change the ZR values in the URBPARM.TBL and to specify the first model level in the namelist.input. None of them works for my case. Even though I specify a higher first model level while running the real.exe, the values change back to the d01 values based on the d01 wrfout files after I run the ndown.exe. Is there any way to bypass this step?

2. When I set the sf_urban_physics = 0 for my d02, I get a segmentation fault.

Has anyone in this forum ever faced a similar problem? I am attaching the rsl.error file and namelist.input file. Any sort of help is highly appreciated.


  • namelist.input
    8.5 KB · Views: 24
  • rsl.error.txt
    701.5 KB · Views: 12
I guess you need to set a higher first model level, then rerun real and wrf.exe for the coarse domain to produce wrfout_d01. Then you can follow the normal processed to run ndown for your child domain.
By the way, if you run wrf-chem, probably you can post your question to wrf-chem forum.