Model name
WRF
Full model name
Weather Research and Forecasting Model
URL
http://www.wrf-model.org
Intended field of application
The WRF-NMM is designed to be a flexible, state-of-the-art atmospheric simulation system suitable for use in a broad range of applications across scales ranging from meters to thousands of kilometers, including: real-time NWP, forecast research, parameterization research, coupled-model applications and teaching.
Model type and dimension
l prognostic. The WRF-NMM is a fully compressible, non-hydrostatic, Three dimensional, meteorological Eulerian model.
Model description summary
The WRF-NMM is a fully compressible, non-hydrostatic mesoscale model with a hydrostatic option. The model uses a terrain following hybrid sigma-pressure vertical coordinate. The grid staggering is the Arakawa E-grid. The same time step is used for all terms. The WRF-NMM model Version 3 supports a variety of capabilities. These include: real-data simulations, non-hydrostatic and hydrostatic (runtime option), full physics options, one-way and two-way nesting, applications ranging from meters to thousands of kilometers.
Model limitations/approximations
Information not available. For more details, please, refer directly to the contact person.
Resolution
Temporal resolution
The general rule for determining the time step of the coarsest grid follows from the CFL criterion. If d is the grid distance between two neighboring points (in diagonal direction on the WRF-NMM's E-grid), dt is the time step, and c is the phase speed of the fastest process, the CFL criterion requires that:
(c*dt)/[d/sqrt(2.)] =1 This gives: dt = d/[sqrt(2.)*c]
A very simple approach is to use 2.25 x (grid spacing in km) or about 330 x (angular grid spacing) to obtain an integer number of time steps per hour.
Horizontal resolution
Information not available. For more details, please, refer directly to the contact person.
Vertical resolution
Information not available. For more details, please, refer directly to the contact person.
Schemes
Advection & Convection
Horizontal: Energy and enstrophy conserving, quadratic conservative, second order
Vertical: Quadratic conservative, second order
TKE, Water species: Upstream, flux-corrected, positive definite, conservative
Planetary Boundary Layer Schemes
Yonsei University scheme; Mellor-Yamada-Janjic scheme; NCEP Global Forecast System scheme; MRF scheme; ACM2 PBL; Quasi-Normal Scale Elimination PBL; Mellor-Yamada Nakanishi and Niino Level 2.5 PBL; Mellor-Yamada Nakanishi and Niino Level 3 PBL ; i. BouLac PBL ; Bougeault-Lacarrère PBL.
Mycrophysis
Kessler scheme; Lin et al. scheme; WRF Single-Moment 3-class scheme; WRF Single-Moment 5-class scheme; Eta microphysics; WRF Single-Moment 6-class scheme; Goddard microphysics scheme; New Thompson et al. scheme; Morrison double-moment scheme; WRF Double-Moment 5-class scheme WRF Double-Moment 6-class scheme; Thompson et al. (2007) scheme.
Chemistry
No chemistry is used, no dispersion of inert pollutants.
Solution technique
Solution technique: 3rd order Runge-Kutta scheme, Advection terms are in the form of a flux divergence. 2nd to 6th order centered and upwind biased schemes: 5th order recommended
Input
Meteorology
Available GRIB datasets: (for input to WPS or WRF SI)
NCEP Final Analysis (FNL from GFS) (ds083.2): 1 degree resolution, every 6 hours
http://dss.ucar.edu/datasets/ds083.2/data/
NCEP/NCAR Reanalysis (ds090.0): 2.5 degree resolution, every 6 hours
http://dss.ucar.edu/datasets/ds090.0/data/pgbf00-grb2d/
NCEP GRIB GDAS (ds083.0): 2.5 degree resolution, every 12 hours. - you may be able to use it if your entire domain stays in one hemisphere.
http://dss.ucar.edu/datasets/ds083.0/data/
NCEP Eta/NAM (ds609.2): 40 km resolution, every 6 hours.
http://dss.ucar.edu/datasets/ds609.2/data/
Land use
By default, the geogrid program will interpolate land use categories from USGS 24- category data. However, the user may select an alternative set of land use categories based on MODIS land-cover classification of the International Geosphere-Biosphere Programme and modified for the Noah land surface model. Although the MODIS-based data contain 20 categories of land use, these categories are not a subset of the 24 USGS categories; users interested in the specific categories in either data set can find a listing of the land use classes in the section on land use and soil categories.
Data assimilation options
3DVar, FGAT, 4DVar
Other input requirements
Several lateral boundary condition (LBC) options are available within the WRF modeling infrastructure. Four types of LBCs are possible within WRF, namely, symmetric, open, periodic and specified.
Output quantities
For output quantities please refer to User's Guide for the NMM Core of the Weather Research and Forecast (WRF) Modeling System Version 3.
Portability and computer requirements
WRF is supported on the following platforms:
