WRF QNSE PBL

[mughalo]

Dear WRF users

I am using WRF version 4.0 and I am trying different PBL schemes. All of the schemes work except for QNSE scheme. The model crashes with a segmentation fault error when the radiation scheme is called. Seems like no issue with the radiation scheme, but more likely, that’s where the error gets picked up. I noted that whichever radiation scheme (lw/sw) or microphysics scheme I use, the length of the simulation always is equal to the value I set for “radt” in the namelist.input. Also tried with both with ERA5 and NCEP data reanalysis data but it didnt work. Also tried lower Fortran optimization, -O2 or -O1 rather than -O3 but nothing seem to work. I am attaching the recent namelist.input to this post.
I would be grateful if someone can point me to the error.

 

[Ming Chen]

Hi,
The namelist looks fine except that the cumulus scheme should be turned on for the 18km domain, i.e.,
cu_physics = 1, 0, 0,

You can also set a larger time step, i..e,
time_step = 72 (or 90)

Also, this is a triply-nested case, which makes it hard to debug what is wrong. I wonder whether you can run this case over a single domain (i.e., max_dom=1) ? This will help us to narrow down possible issues.

Since the grid number is pretty small (50 x 50), I suggest you run this case with no more than 4 processors.

 

[mughalo]

Hi
Thanks for your prompt response. I have submitted the runs with the options you have provided.
Do you mean to only use 4 processors from a single node ? I am currently using the following

SBATCH --ntasks=96
SBATCH --ntasks-per-node=24
SBATCH --time=00:30:00

This allows me to select 4 nodes with 24 tasks per node.

 

[mughalo]

Please see the rsl.error files for each of the options used above. None of them worked for me.

 

[Ming Chen]

The number of processors are too large for this case. You may need to run with a single node and use only 4 processors out of the 24.
With such a large number of processors you are using at present, domain decomposition would be wrong.

 

[mughalo]

I reduced to 4 processors but I still see the same problem. I am not sure about the issue

 

[Anie_Lal]

I reduced to 4 processors but I still see the same problem. I am not sure about the issue

Hi
Where you able to solve the issue?
I am facing the same error. Model is working fine for all other pbl_schemes except QNSE.

I gives a segmentation error after a few time steps.
I am attaching the namelist and rsl error log.

Looking forward to any kind of help.

 

[mughalo]

No sorry was still not able to resolve the problem.
Probably Jimmy Dudhia can help us out here. I think it has something to do with its link to the radiation schemes and with the landsurface model. But not sure

 

[mhafsah]

I am having the same problem. could you solve it? these are my physics options (below). I did not use mfshconv at first but it did not matter anyway.

&physics
mp_physics = 8, 8,
ra_lw_physics = 4, 4,
ra_sw_physics = 4, 4,
radt = 9, 9,
sf_sfclay_physics = 4, 4,
sf_surface_physics = 2, 2,
bl_pbl_physics = 4, 4,
bldt = 0, 0,
cu_physics = 1, 0,
cudt = 0, 0,
mfshconv = 1, 1,
isfflx = 1,
ifsnow = 1,
icloud = 1,
surface_input_source = 3,
num_soil_layers = 4,
num_land_cat = 21,
sf_urban_physics = 0, 0,
cu_rad_feedback = .true.,
bl_mynn_tkeadvect = .true.,.true.,
tke_budget = 1, 1,
!!sst_update = 1,
!!windfarm_opt = 0, 1,
!!windfarm_tke_factor = 0,

 

[mughalo]

Hi
I am not able to solve it still.
I have a hunch that it has something to do with the grid configuration means the scheme could work well for high resolution data but not sure someone needs to test it or may be NCAR can provide a response.
Apologies

 

[mhafsah]

Hi
I am not able to solve it still.
I have a hunch that it has something to do with the grid configuration means the scheme could work well for high resolution data but not sure someone needs to test it or may be NCAR can provide a response.
Apologies

no no you are fine. I will get back to this thread if I can solve it (or get any answer from anyone) and I would ask you to do the same. Thanks for the reply!

 

[Ming Chen]

I did some broad tests using the QNSE PBL scheme. Below is details of one test I did:

(1) The forcing data is GFS global analysis data

(2) The namelist options are the same as that posted above. Below are a few key options:
&physics
mp_physics = 8, 8,
ra_lw_physics = 4, 4,
ra_sw_physics = 4, 4,
radt = 9, 9,
sf_sfclay_physics = 4, 4,
sf_surface_physics = 2, 2,
bl_pbl_physics = 4, 4,
...
...

(3) I ran cases over CONUS at resolution of 15km.

WRFV4.5 and WRFV4.6 both work fine. However, WRFV4.0 failed with segmentation fault. The model crashed due to errors in surface scheme (i.e., Flerchinger USEd in NEW version. Iterations= 10)

We didn't find a quick fix to the issue and it is not our top priority to debug older version of WRF. Therefore, I would suggest staying with the
latest version of WRF, which works with the QNSE PBL schemes.

 

[mhafsah]

I did some broad tests using the QNSE PBL scheme. Below is details of one test I did:

(1) The forcing data is GFS global analysis data

(2) The namelist options are the same as that posted above. Below are a few key options:
&physics
mp_physics = 8, 8,
ra_lw_physics = 4, 4,
ra_sw_physics = 4, 4,
radt = 9, 9,
sf_sfclay_physics = 4, 4,
sf_surface_physics = 2, 2,
bl_pbl_physics = 4, 4,
...
...

(3) I ran cases over CONUS at resolution of 15km.

WRFV4.5 and WRFV4.6 both work fine. However, WRFV4.0 failed with segmentation fault. The model crashed due to errors in surface scheme (i.e., Flerchinger USEd in NEW version. Iterations= 10)

We didn't find a quick fix to the issue and it is not our top priority to debug older version of WRF. Therefore, I would suggest staying with the
latest version of WRF, which works with the QNSE PBL schemes.

Hi Ming, thank you for your response. Just to report to you know that I am using wrfv4.5 with era5 as forcing data and still have got the same issue.

 

[Ming Chen]

@ mhafsah @mughalo

I am sorry to get back to you late but this is because I have been extremely busy in the past 2-3 weeks.

For the issues related to QNSE, I am perplexed by the errors you reported, ---- I cannot repeat the errors using the same options and similar resolution....

please keep me updated if you figure out the reason. Thanks in advance.