Physics Suites

Physics Contents

WRF Physics Overview
Cumulus Parameterization
Microphysics
Radiation
Planetary Boundary Layer (PBL) Physics
Surface Physics
Using Physics Suites
Physics Options for Specific Applications

Using Physics Suites

A WRF physics suite is a set of physics options that performs well for a given application and is supported by a sponsoring group. Suites may offer guidance to users in applying WRF, improve understanding of model performance, and facilitate model advancement.

When running WRF, a suite of physics schemes can be set by using the physics_suite namelist option. The physics options covered by this suite specification are:

mp_physics
cu_physics
bl_pbl_physics
sf_sfclay_physics
sf_surface_physics
ra_sw_physics
ra_lw_physics

There are currently 2 available approved physics suite options: the NCAR Convection-permitting Suite (CONUS), and the NCAR Tropical Suite (tropical) that can be specified in the &physics section of the namelist.input file. By simply setting the “physics_suite” namelist parameter, the included physics schemes are assumed and, therefore, the specific schemes (e.g., mp_physics, cu_physics, etc.) do not need to be set. These two suites consist of a combination of physics options that have been highly tested and have shown reasonable results.

A summary of the physics schemes used in the simulation are printed to the WRF output log (e.g., rsl.out.0000).

NCAR Convection-permitting Suite

physics_suite=’CONUS’

Real-time forecasting focused on convective weather over the contiguous U.S.

Physics Type	Scheme Name	Namelist Option
Microphysics	Thompson	mp_physics=8
Cumulus	Tiedtke	cu_physics=6
Longwave Radiation	RRTMG	ra_lw_physics=4
Shortwave Radiation	RRTMG	ra_sw_physics=4
PBL	MYJ	bl_pbl_physics=2
Surface Layer	MYJ	sf_sfclay_physics=2
LSM	Noah	sf_surface_physics=2

Note

See NCAR Convection-permitting Physics Suite for WRF for additional details.

NCAR Tropical Suite

physics_suite=’tropical’

Real-Time forecasting focused on tropical storms and tropical convection

Note

This is the same as the “mesoscale_reference” suite in the MPAS model.

Physics Type	Scheme Name	Namelist Option
Microphysics	WSM6	mp_physics=6
Cumulus	New Tiedtke	cu_physics=16
Longwave Radiation	RRTMG	ra_lw_physics=4
Shortwave Radiation	RRTMG	ra_sw_physics=4
PBL	YSU	bl_pbl_physics=1
Surface Layer	MM5	sf_sfclay_physics=91
LSM	Noah	sf_surface_physics=2

Note

See NCAR Tropical Physics Suite for WRF for additional details.

Overriding Physics Suite Options

To override any of the above options, simply add that particular parameter to the namelist.

Example 1 : You wish to use the CONUS suite but would like to turn off cu_physics for domain 3 (note: a setting of “-1” means the default setting is used):

physics_suite = 'CONUS' |br|
cu_physics = -1, -1, 0

Example 2 : You wish to use the CONUS suite but would like to use a different cu_physics option, and to turn cu_physics off for domain 3:

physics_suite = 'CONUS'
cu_physics = 2, 2, 0

Next section: Physics Options for Specific Applications