question about snow in WRF

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pengyuan
Posts: 6
Joined: Mon Nov 05, 2018 1:44 am

question about snow in WRF

Post by pengyuan » Mon Nov 05, 2018 1:57 am

Dear Sir/Madam,
I am using WRFv3.5.1 to simulate snow storm.
The observation about a snow storm is 20 mm, which is accumulated total snow during a period.
I want to know which variable about snow should be used for denoting the observation.
I use ARWpost to process wrfout*.nc files to GrADS format.
I am wondering which variable in the *ctl file should be used for representing snow mentioned above.
Best,
Pengyuan

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

Re: question about snow in WRF

Post by kwerner » Mon Nov 05, 2018 11:22 pm

Hi Pengyuan,
Unfortunately there is not a built-in snow accumulation function in ARWpost. You may need to create one for this, and can possible follow the precipitation accumulation script (rain.gs). You will first need to make sure that you are outputting snow accumulation to your wrfout* (history) files when running WRF. You can probably use the variable ACSNOW, but you will need to turn it on, as the registry file does not have it automatically output. There are 2 ways to turn it on:
1) Modify the WRF/Registry/Registry.EM_COMMON file. In this line:

Code: Select all

state    real   ACSNOW           ij     misc        1         -      rd=(interp_mask_field:lu_index,iswater)u=(copy_fcnm)       "ACSNOW"           "ACCUMULATED SNOW"         "kg m-2"
You'll need to add an 'h' for 'history in the I/O column, so that it reads:

Code: Select all

state    real   ACSNOW           ij     misc        1         -      rhd=(interp_mask_field:lu_index,iswater)u=(copy_fcnm)       "ACSNOW"           "ACCUMULATED SNOW"         "kg m-2"
The downfall with this option is that you will have to clean, reconfigure, and recompile the model.

2) A simpler option may be to use the Runtime I/O option. You can read more about that here:
http://www2.mmm.ucar.edu/wrf/users/docs ... #runtimeio
NCAR/MMM

pengyuan
Posts: 6
Joined: Mon Nov 05, 2018 1:44 am

Re: question about snow in WRF

Post by pengyuan » Tue Nov 06, 2018 1:16 am

Hi, Kwerner
Thank you for your help.
I will follow your guidance and try it.
Best,
Pengyuan

pengyuan
Posts: 6
Joined: Mon Nov 05, 2018 1:44 am

Re: question about snow in WRF

Post by pengyuan » Tue Nov 06, 2018 1:23 am

Hi, Kwerner
Can you do me a favor ? put a rain.gs file for refrence.
I do not have that gs script.
Thanks in advance.
Pengyuan

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

Re: question about snow in WRF

Post by kwerner » Tue Nov 06, 2018 6:02 pm

Pengyuan,
Sure! I'm attaching it. Just for reference, these scripts can be found in the ARWpost/scripts/ directory.
Attachments
rain.gs
(904 Bytes) Downloaded 40 times
NCAR/MMM

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