WRF ARW User's Guide - MMM - UCAR

2.1 Longwave Radiation (ra_lw_physics)
MODEL
a. RRTM scheme: Rapid Radiative Transfer Model. An accurate scheme using lookup
tables for efficiency. Accounts for multiple bands, trace gases, and microphysics
species (ra_lw_physics = 1).
b. GFDL scheme: Eta operational radiation scheme. An older multi-band scheme with
carbon dioxide, ozone and microphysics effects (99).
c. CAM scheme: from the CAM 3 climate model used in CCSM. Allows for aerosols
and trace gases (3).
d. RRTMG scheme. A new version of RRTM added in Version 3.1 (4). It includes the
MCICA method of random cloud overlap.
2.2 Shortwave Radiation (ra_sw_physics)
a. Dudhia scheme: Simple downward integration allowing efficiently for clouds and
clear-sky absorption and scattering. When used in high-resolution simulations, sloping
and shadowing effects may be considered (ra_sw_physics = 1).
b. Goddard shortwave: Two-stream multi-band scheme with ozone from climatology
and cloud effects (2).
c. GFDL shortwave: Eta operational scheme. Two-stream multi-band scheme with
ozone from climatology and cloud effects (99).
d. CAM scheme: from the CAM 3 climate model used in CCSM. Allows for aerosols
and trace gases (3).
e. RRTMG shortwave. A new shortwave scheme with the MCICA method of random
cloud overlap (4). New in Version 3.1.
f. Held-Suarez relaxation. A temperature relaxation scheme designed for idealized
tests only (31).
3.1 Surface Layer (sf_sfclay_physics)
a.MM5 similarity: Based on Monin-Obukhov with Carslon-Boland viscous sub-layer
and standard similarity functions from look-up tables (sf_sfclay_physics = 1).
b. Eta similarity: Used in Eta model. Based on Monin-Obukhov with Zilitinkevich
thermal roughness length and standard similarity functions from look-up tables(2).
c. Pleim-Xiu surface layer. (7). New in Version 3.0.
d. QNSE surface layer. Quasi-Normal Scale Elimination PBL scheme’s surface layer
option (4). New in Version 3.1.
e. MYNN surface layer. Nakanishi and Niino PBL’s surface layer scheme (5). New in
Version 3.1.
3.2 Land Surface (sf_surface_physics)
a. 5-layer thermal diffusion: Soil temperature only scheme, using five layers
(sf_surface_physics = 1).
WRF-ARW V3: User’s Guide 5-25