Matching WRF and MPAS physics

[ArashC]

Hello,

Sorry for the basic question but I was a bit confused by MPAS manual. Is it possible to exactly match the physics options for WRF and MPAS? I already have a WRF namelist and I want to use the same physics schemes for my MPAS run. Thanks so much.

Best,

 

[kwerner]

Hi,
Many of the same physics that are available for WRF are also available for MPAS, but not all. See this page, which describes supported physics suites, but if you scroll down further, information on the individual available physics options for MPAS are listed.

 

[Ming Chen]

The physics suite "Mesoscale_reference" corresponds to the suite "Tropical" in WRF. However, some other options should also be set to make the physics consistent between the two models. Below is a detailed list:
config_o3climatology = True (MPAS) and O3input = 2 (WRF)
config_microp_re = True (MPAS) and use_mp_re = 1 (WRF)
config_gwdo_scheme = off (MPAS) and gwd_opt = 0 (WRF)
sfc_snowalbedo = true(MPAS) and rdmaxalb=true (WRF)
Please let me know if you ahve more questions. Thanks.

 

[ArashC]

Thank you so much. Is there a way to also make "convection_permitting" in MPAS equal to physics in WRF?

 

[Ming Chen]

"convection_permitting" in MPAS is equivalent to 'CONUS' in WRF.

 

[ArashC]

Thanks so much. Do I need to implement the following as well?

config_o3climatology = True (MPAS) and O3input = 2 (WRF)
config_microp_re = True (MPAS) and use_mp_re = 1 (WRF)
config_gwdo_scheme = off (MPAS) and gwd_opt = 0 (WRF)
sfc_snowalbedo = true(MPAS) and rdmaxalb=true (WRF)

 

[Ming Chen]

Yes you need to specify these options, no matter what suites you use.

 

[ArashC]

Hello again,

The options worked out ok for MPAS. Now my WRF looks like following and I get an error.

&physics
physics_suite = 'CONUS'
mp_physics = -1, -1,
cu_physics = -1, -1,
ra_lw_physics = -1, -1,
ra_sw_physics = -1, -1,
bl_pbl_physics = -1, -1,
sf_sfclay_physics = -1, -1,
sf_surface_physics = -1, -1,
radt = 15, 15,
bldt = 0, 0,
cudt = 0, 0,
icloud = 1,
num_land_cat = 21,
sf_urban_physics = 0, 0,
fractional_seaice = 1,
O3input = 2,
use_mp_re = 1,
gwd_opt = 0,
rdmaxalb =.true.,


------ ERROR while reading namelist physics ------
Maybe here?: use_mp_re = 1,
Maybe here?: gwd_opt = 0,
-------------- FATAL CALLED ---------------
FATAL CALLED FROM FILE: <stdin> LINE: 11540
ERRORS while reading one or more namelists from namelist.input.

I am using version 4.4. Please let me know how I should modify the physics.

Thanks so much.

 

[Ming Chen]

The option " gwd_opt " belongs to &dynamics. You put it to &physics, which is why WRF failed.

 

[ArashC]

Thanks so much. This is my last question. Is there a way to make WRF and MPAS vertical layers similar? If not exact, an approximation works too.

 

[Ming Chen]

This is a good question. Yes you need to try to make the vertical levels close to each other between WRF and MPAS. We did so before when we compared WRF and MPAS performance. Unfortunately I didn't save the documents. You have to make it yourself, and I suppose this is not a hard issue.