Urban-BEM parameters in WRF-4.4.2 version

[sadya_islam20]

Previously, I used the WRF 3.9.1.1 version, and to run Urban-BEM (sf_urban_physics = 3), I needed to add this line in the namelist:
" num_urban_layers = 5400 "

But, in the newer version, adding this line aborts the real.exe run:

"
FATAL CALLED FROM FILE: <stdin> LINE: 11540
ERRORS while reading one or more namelists from namelist.input.
-------------------------------------------
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0

"

Is this " num_urban_layers = 5400 " option removed from the newer version? Should I not use it anymore?

 

[kwerner]

Hi,
This was changed beginning in V4.1, so the variable "num_urban_layers" is no longer valid. The description of the change is:

• BEP and BEM: These multi-layer urban models pack 4D, 5D, and 6D arrays into 3D. The original code used one dimension (num_urban_layers) which depends on the largest 6D array. With no answer changes, the new code creates separate mapping for the different urban arrays so that the arrays are maximally filled for each urban array. Compared to the original code, the memory cost (relative to a non-urban run) of using UCM is reduced from 31% to 5%, BEP from 31% to 15% and BEM from 707% to 274%, equivalent to a 20%, 45% and 64% reduction in memory used, respectively. When users run BEP or BEM, new namelist values for the urban dimensions must be set (num_urban_ndm, num_urban_ng, num_urban_nwr, num_urban_ngb, num_urban_nf, num_urban_nz, num_urban_nbui) and equal the values in the BEP and BEM modules (see run/README.namelist)

 

[sadya_islam20]

Hello,

So, I added all those options to the namelist, but I am still getting a fatal error. If I do not add any of these options, real.exe runs successfully. I attached the namelist.input file.

I found this post on the same issue: Running WRF BEPBEM in V4 and on

My understanding is that only adding "sf_urban_physics = 3, 3, 3" is sufficient for running the BEM model.

What is your recommendation?

Thanks!

 

[kwerner]

It's certainly okay to only run with sf_urban_physics turned on, and, as a matter of fact, the "num_urban_*" parameters are listed in the registry as "derived" and not namelist options, even though in that release statement, it says they ARE namelist parameters. That is confusing, so I apologize. But that's probably why you are getting the errors.

 

[sadya_islam20]

It's certainly okay to only run with sf_urban_physics turned on, and, as a matter of fact, the "num_urban_*" parameters are listed in the registry as "derived" and not namelist options, even though in that release statement, it says they ARE namelist parameters. That is confusing, so I apologize. But that's probably why you are getting the errors.

Thanks! I'll then just enable sf_urban_physics for Urban-BEM.