ACM2 pbl error

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neel14
Posts: 96
Joined: Fri Mar 15, 2019 6:52 am

ACM2 pbl error

Post by neel14 » Sat Feb 15, 2020 8:23 am

Hi,
I am getting this error:
RIBX never exceeds RIC, RIB(i,kte) = NaN THETAV(i,1) = 309.9481 MOL= -0.5745613 TCONV = NaN WST = -1.994674 KMIX = 1 UST = -0.1035916 TST = -0.9554436 U,V = 0.4300827 0.2205904 I,J= 206 57
I am using,
sf_sfclay_physics = 7, 7, 7,
sf_surface_physics = 2, 2, 2,
bl_pbl_physics = 7, 7, 7,
with MCD12Q1, 17 category data. The model crashes in d02 after running for 96 hours.
There are similar topics in this forum but the solutions aren't working for me. I only have issue with this pbl scheme, other pbl schemes are working. I am using the latest versions of WPS and WRF.

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ACM2 pbl error

Post by kwerner » Wed Feb 19, 2020 10:30 pm

Hi,
Have you tested this with the following settings?
sf_sfclay_physics = 7, 7, 7,
sf_surface_physics = 7, 7, 7,
bl_pbl_physics = 7, 7, 7,

The Pleim-Xu sfclay scheme was designed to work specifically with the Pleim-Xu surface scheme, and the ACM2 PBL scheme. There is no testing that has taken place with other combinations, and therefore we cannot guarantee success with others.
NCAR/MMM

neel14
Posts: 96
Joined: Fri Mar 15, 2019 6:52 am

Re: ACM2 pbl error

Post by neel14 » Thu Feb 20, 2020 5:00 am

Hi,
Yes I have tried that combination but it doesn't work for me since PXLSM requires MODIS 20 or 21 category data whereas I am using 17. I had got another error for that.

Is there any way to make the 17 category work for PXLSM, since in my domain categories 18-21 in MODIS are almost non existant or taken care by other categories?

Also I have been able to run successfully with
sf_sfclay_physics = 1,1,1,
sf_surface_physics = 2, 2, 2,
bl_pbl_physics = 7, 7, 7
But mixing ratio is very much underestimated. Could you suggest some changes with the namelist to improve the mixing ratio without changing the above configuration.

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ACM2 pbl error

Post by kwerner » Mon Feb 24, 2020 4:24 pm

Can you let me know which version of WRF you are using? Thanks.
NCAR/MMM

neel14
Posts: 96
Joined: Fri Mar 15, 2019 6:52 am

Re: ACM2 pbl error

Post by neel14 » Tue Feb 25, 2020 3:01 am

I am using 4.1.3.

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ACM2 pbl error

Post by kwerner » Mon Mar 02, 2020 6:42 pm

Hi,
It's possible that you could change any land categories above 18 in your domain to values >=17, so that you only have 17 categories.
As for the problems you are seeing with mixing ratio, it again could be the combination you're using. It's hard to say. Take a look at this document from the developers of the Pleim-Xu and ACM2 schemes to see if it's helpful to you in any way:
https://www2.mmm.ucar.edu/wrf/users/docs/PX-ACM.pdf
NCAR/MMM

momodiallosn
Posts: 11
Joined: Mon Jul 22, 2019 6:49 am

Re: ACM2 pbl error

Post by momodiallosn » Wed Apr 07, 2021 7:27 am

Hi,
I encountered the problem and solved it without using modis_30s. I am using usgs_30s and corine land use with 100m resolution.
For people facing the same issue you may want to lower the nudging coefficient values guv, gt and gq.
For guv=gt=qg > 0.01 I faced RIBX never exceeds RIC, RIB(i,kte) . I finally setlled up with following parameters:

grid_fdda = 1,
grid_sfdda = 1,
pxlsm_soil_nudge = 1,
gfdda_interval_m = 180,
guv = 0.0001,
gt = 0.0001,
gq = 0.00001,
guv_sfc = 0.0000,
gt_sfc = 0.0000,
gq_sfc = 0.0000,

Sincerely yours

kwerner
Posts: 2287
Joined: Wed Feb 14, 2018 9:21 pm

Re: ACM2 pbl error

Post by kwerner » Fri Apr 09, 2021 11:42 pm

@momodialiosn,
Thank you for posting your fix to the problem!
NCAR/MMM

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