WRF-NMM Model Version 3 (April 2008) ---------------------------- WRF-NMM PUBLIC DOMAIN NOTICE ---------------------------- WRF-NMM was developed at National Centers for Environmental Prediction (NCEP), which is part of NOAA's National Weather Service. As a government entity, NCEP makes no proprietary claims, either statutory or otherwise, to this version and release of WRF-NMM and consider WRF-NMM to be in the public domain for use by any person or entity for any purpose without any fee or charge. NCEP requests that any WRF user include this notice on any partial or full copies of WRF-NMM. WRF-NMM is provided on an "AS IS" basis and any warranties, either express or implied, including but not limited to implied warranties of non-infringement, originality, merchantability and fitness for a particular purpose, are disclaimed. In no event shall NOAA, NWS or NCEP be liable for any damages, whatsoever, whether direct, indirect, consequential or special, that arise out of or in connection with the access, use or performance of WRF-NMM, including infringement actions. ================================================ V3 Release Notes: ----------------- This is the main directory for the WRF Version 3 source code release. - For directions on compiling WRF for NMM, see below or the WRF-NMM Users' Web page (http://www.dtcenter.org/wrf-nmm/users/) - Read the README.namelist file in the run/ directory (or on the WRF-NMM Users' page), and make changes carefully. For questions, send mail to wrfhelp@ucar.edu ====================================== The ./compile script at the top level allows for easy selection of NMM and ARW cores of WRF at compile time. - Specify your WRF-NMM option by setting the appropriate environment variable: setenv WRF_NMM_CORE 1 setenv WRF_NMM_NEST 1 (if nesting capability is desired) - The Registry files for NMM and ARW are not integrated yet. There are separate versions: Registry/Registry.NMM <-- for NMM Registry/Registry.NMM_NEST <-- for NMM with nesting Registry/Registry.EM <-- for ARW (formerly known as Eulerian Mass) How to configure, compile and run? ---------------------------------- - In WRFV3 directory, type: configure this will create a configure.wrf file that has appropriate compile options for the supported computers. Edit your configure.wrf file as needed. Note: WRF requires netCDF library. If your netCDF library is installed in some odd directory, set environment variable NETCDF before you type 'configure'. For example: setenv NETCDF /usr/local/lib32/r4i4 - Type: compile nmm_real - If sucessful, this command will create nmm_real.exe and wrf.exe in directory main/, and the appropriate executables will be linked into the run directories under test/nmm_real, or run/. - cd to the appropriate test or run directory to run "nmm_real.exe" and "wrf.exe". - Place files from WPS (met_nmm.*, geo_nmm_nest*) in the appropriate directory, type real_nmm.exe to produce wrfbdy_d01 and wrfinput_d01. Then type wrf.exe to run. - If you use mpich, type mpirun -np number-of-processors wrf.exe ============================================================================= What is in WRF-NMM V3.0? * Dynamics: - The WRF-NMM model is a fully compressible, non-hydrostatic model with a hydrostatic option. - Supports One-way and two-way static nesting. - The terrain following hybrid pressure sigma vertical coordinate is used. - The grid staggering is the Arakawa E-grid. - The same time step is used for all terms. - Time stepping: - Horizontally propagating fast-waves: Forward-backward scheme - Veryically propagating sound waves: Implicit scheme - Advection (time): T,U,V: - Horizontal: The Adams-Bashforth scheme - Vertical: The Crank-Nicholson scheme TKE, water species: Forward, flux-corrected (called every two timesteps). - Advection (space): T,U,V: - Horizontal: Energy and enstrophy conserving, quadratic conservative,second order - Vertical: Quadratic conservative,second order TKE, - Water species: Upstream, flux-corrected, positive definite, conservative - Horizontal diffusion: Forward, second order "Smagorinsky-type" - Vertical Diffusion: See "Free atmosphere turbulence above surface layer" section in "Physics" section given in below. * Physics: - Explicit Microphysics (WRF Single Moment 5 and 6 class / Ferrier (Used operationally at NCEP.)/ Thompson [a new version in 2.2]) - Cumulus parameterization (Kain-Fritsch with shallow convection / Betts-Miller-Janjic (Used operationally at NCEP.)/ Grell-Devenyi ensemble / Simplified Arakawa-Schubert) - Free atmosphere turbulence above surface layer: Mellor-Yamada-Janjic (Used operationally at NCEP.) - Planetary boundary layer: YSU / Mellor-Yamada-Janjic (Used operationally at NCEP.) / GFS - Surface layer: Similarity theory scheme with viscous sublayers over both solid surfaces and water points (Janjic - Used operatinally at NCEP). / GFS / YSU - Slab soil model: Noah land-surface model (4-level - Used operationally at NCEP) / RUC LSM (6-level) - Radiation: - Longwave radiation: GFDL Scheme (Fels-Schwarzkopf) (Used operationally at NCEP.) / RRTM - Shortwave radiation: GFDL-scheme (Lacis-Hansen) (Used operationally at NCEP.) / Dudhia - Gravity wave drag: none * WRF Software: - Hierarchical software architecture that insulates scientific code (Model Layer) from computer architecture (Driver Layer) - Multi-level parallelism supporting shared-memory (OpenMP), distributed-memory (MPI), and hybrid share/distributed modes of execution - Serial compilation can be used for single-domain runs but not for runs with nesting at this time. - Active data registry: defines and manages model state fields, I/O, configuration, and numerous other aspects of WRF through a single file, called the Registry - Enhanced I/O options: NetCDF and Parallel HDF5 formats Five auxiliary history output streams separately controllable through the namelist Output file names and time-stamps specifiable through namelist - Testing: Various regression tests are performed on HP/Compaq systems at NCAR/MMM whenever a change is introduced into WRF cores. - Efficient execution on a range of computing platforms: IBM SP systems, (e.g. NCAR "bluevista","blueice" and NCEP's "blue", Power4-based system) HP/Compaq Alpha/OSF workstation, SMP, and MPP systems (e.g. Pittsburgh Supercomputing Center TCS) SGI Origin and Altix Linux/Intel IA64 MPP (HP Superdome, SGI Altix, NCSA Teragrid systems) IA64 SMP Pentium 3/4 SMP and SMP clusters (NOAA/FSL iJet system) PGI and Intel compilers supported Alpha Linux (NOAA/FSL Jet system) Sun Solaris (single threaded and SMP) Cray X1 HP-UX Other ports under development: NEC SX/6 Fujitsu VPP 5000 - RSL_LITE: communication layer, scalable to very large domains - ESMF Time Management, including exact arithmetic for fractional time steps (no drift); model start, stop, run length and I/O frequencies are now specified as times and time intervals - Improved documentation, both on-line (web based browsing tools) and in-line --------------------------------------------------------------------------