urban configuration in WRF

[JulioC]

Hi All,

I have a question regarding urban configuration in WRF . When using sf_urban_physics = 2 and there is no URB_PARAM and FRC_URB2D information. What WRF does with the 3 Urban categories that appear in the URBPARM.TBL file?

How I can create NUDAPT44_1km and urbfrac_nlcd2011 equivalent files for my domain?


Cheers

Julio

 

[Ming Chen]

Julio,
URB_PARAM is only available in REAL, and some variables related to urban physics are derived from URB_PARAM in REAL program. FRC_URB2D is introduced in WRFV4.0 no matter whether urban physics is turned on or off. Can you update WRF to newer version like WRFV4.0.3?
I believe that FRC_URB2D is derived from the NLCD30s data.

 

[JulioC]

Thanks Ming,

I'm using WRFV4.0.3 and real.
I'm modelling a Domain in South America and I'm succesfully using the urban physics. What I don't understand well is how WRF (or WPS) distributes the urban land use into the three categories used by URBPRAM.TBL (Commercial, high density residential and low density residential)


Many thanks

Julio

 

[Ming Chen]

Julio,

You need to have the high-resolution landuse dataset that includes the three urban categories, and incorporate this information into LANDUSEF.
Please see the document here

http://www2.mmm.ucar.edu/wrf/users/tutorial/201901/duda_wps_advanced.pdf

pages 17-21 give detailed description how to do it.

 

[JulioC]

Thanks Ming,

Another question, What if you don't have the three urban categories specified, in that case WRF uses an average of the 3 categories parametrization from URBPARM.TBL or uses only 1 of the 3 categories?

Cheers

Julio

 

[Ming Chen]

In that case WRF will set the urban type as the high-intensity and use the corresponding values in URBPARM.TBL.

 

[JulioC]

Thanks