1. How to set up and run WRF model

2. Outline n How to download and compile the WRF code? n Namelist n Input and output files

3. How to download and compile WRF? n Download WRF source code from http://www.wrf-model.org/users/download.html n What you get is WRFV1.TAR.gz n After gunzip and untar the file, you should see a directory WRFV1 n cd to WRFV1 directory, and you should see..

4. WRFV1 directory CHANGES Makefile README README_test_cases Registry/ arch/ clean compile configure dyn_eh/ External/ frame/ inc/ main/ phys/ run/ share/ test/ tool/

5. Type ‘configure’ to create configure.wrf file for your particular machine: azalea2:/mmmtmp/wrfhelp/WRFV1>configure checking for perl5... no checking for perl... found /usr/local/bin/perl (perl) Will use NETCDF in dir: /usr/local/netcdf ------------------------------------------------------- Please select from among the following supported platforms. 1. Compaq OSF1 alpha (single-threaded) 2. Compaq OSF1 alpha SM (OpenMP) 3. Compaq OSF1 alpha DM/SM (RSL, MPICH, RSL IO, OpenMP) 4. Compaq OSF1 alpha DM/SM (RSL, DECMPI, RSL IO, OpenMP) Enter selection [1-4] : 1

6. You’ll see: You have chosen: Compaq OSF1 alpha (single-threaded) These are the default options for this platform: -------------------------------------------------------------- # OMP = OMPCPP = FC = f90 CC = cc CFLAGS = FCOPTIM = -fast -O4 -inline all …… -------------------------------------------------------------- These will be written to the file configure.wrf here in the top-level directory. If you wish to change settings, please edit that file. If you wish to change the default options, edit the file: arch/configure.defaults Configuration successful. To build the model type compile.

7. n After one obtains the configure.wrf file, type compile eh_real to compile If compile is successful, you should have two executables built in directory main/: real.exe wrf.exe And these executables are linked to./test/eh_real/

8. test/eh_real directory These are what one’d see in test/eh_real/ directory: LANDUSE.TBL RRTM_DATA namelist.input real.exe ->../../main/real.exe wrf.exe ->../../main/wrf.exe

9. n Before you run real and wrf, edit the namelist for runtime options

10. &namelist_01 time_step_max = 1, number of time steps to run max_dom = 1, number of domains (leave as is) dyn_opt = 3, dynamics option: 1 = leapfrog, not yet implemented 2 = Runge-Kutta 2nd order 3 = Runge-Kutta 3rd order diff_opt = 1, diffusion option: 1 = old diffusion scheme (uses khdiv,kvdif) 2 = new diffusion scheme (uses km_opt) (stress form) km_opt = 1, eddy coefficient option 1 = constant (from khdiv kvdif) 2 = 1.5 order TKE closure 3 = Smagorinsky first order closure damp_opt = 1, upper level damping flag 0 = without damping 1 = with damping Description of namelist_01

11. ISFFLX = 1, heat and moisture fluxes from the surface 1 = with fluxes from the surface 0 = no flux from the surface IFSNOW = 0, snow-cover effects 1 = with snow-cover effect 0 = without snow-cover effect ICLOUD = 1, cloud effect to the optical depth in radiation 1 = with cloud effect 0 = without cloud effect Description of namelist_01

12. num_soil_layers = 5, number of soil layers in land surface model spec_bdy_width= 5, number of rows for specified boundary value nudging spec_zone = 1, number of points in specified zone (spec b.c. option) relax_zone= 4, number of points in relaxation zone (spec b.c. option) tile_sz_x = 0, number of points in tile x direction tile_sz_y = 0, number of points in tile y direction numtiles= 1, number of tiles per patch (alternative to above two) debug_level = 0/ 50,100,200,300 values give increasing prints Description of namelist_01

13. &namelist_02 grid_id = 1, domain identifier level = 1, domain nest level s_we = 1, start index in x (west-east) direction e_we = 32, end index in x (west-east) direction s_sn = 1, start index in y (south-north) direction e_sn = 32, end index in y (south-north) direction s_vert = 1, start index in z (vertical) direction e_sn = 31, end index in z (vertical) direction Description of namelist_02

14. time_step_count_output = 10, history output frequency in timesteps frames_per_outfile = 10, output times per history file time_step_count_restart = 10, restart output frequency in timesteps time_step_begin_restart = 0, timestep for restart run to begin 0=not a restart time_step_sound =4, number of sound steps per timestep

15. &namelist_03 dx = 200, grid length in x direction dy = 200, grid length in y direction dt = 2., time-step for advection ztop = 20000., the height of the model top zdamp = 5000., damping depth from model top dampcoef = 0.2, damping coefficient (dampcoef <= 0.25) smdiv = 0, divergence damping (0.1 is typical) epssm =.1, time off-centering for vertical sound waves khdif = 0, horizontal diffusion constant (m^2/s) kvdif = 0, vertical diffusion constant (m^2/s) mix_cr_len = 200, the critical value of the mixing length for isotropic and anisotropic diffusion Description of namelist_03

16. radt = 0, minutes between radiation physics calls bldt = 0, minutes between boundary-layer physics calls cudt = 0, minutes between cumulus physics calls julyr = 0, Julian Year for model start julday = 1, Julian Day for model start gmt = 0./ GMT time for model start Description of namelist_03

17. &namelist_04 periodic_x =.false., periodic boundary conditions in x direction symmetric_xs =.false., symmetric boundary conditions at x start (west) symmetric_xe =.false., symmetric boundary conditions at x end (east) open_xs =.false., open boundary conditions at x start (west) open_xe =.false., open boundary conditions at x end (east) periodic_y =.false., periodic boundary conditions in y direction symmetric_ys =.false., symmetric boundary conditions at y start (south) symmetric_ye =.false., symmetric boundary conditions at y end (north) open_ys =.false., open boundary conditions at y start (south) open_ye =.false., open boundary conditions at y end (north) nested =.false., nested boundary conditions (inactive) specified =.false., specified boundary conditions (inactive) top_radiation=.false., upper radiative boundary conditions (inactive) Description of namelist_04

18. chem_opt = 0, chemistry option mp_physics microphysics option = 0, no microphysics = 1, Kessler scheme = 2, Lin et al. scheme = 3, NCEP 3-class simple ice scheme = 4, NCEP 5-class scheme ra_lw_physics longwave radiation option = 0, no longwave radiation = 1, rrtm scheme ra_sw_physics shortwave radiation option = 0, no shortwave radiation = 1, Dudhia scheme = 2, Goddard short wave Description of namelist_04

19. bl_sfclay_physics surface-layer option = 0, no surface-layer = 1, Monin-Obukhov scheme bl_surface_physics land-surface option = 0, no land-surface = 1, thermal diffusion scheme bl_pbl_physics boundary-layer option = 0, no boundary-layer = 1, mrf scheme cu_physics cumulus option = 0, no cumulus = 1, Kain-Fritsch scheme = 2, Betts-Miller-Janjic scheme Description of namelist_04

20. h_mom_adv_order = 5, horizontal momentum advection order (5=5th, etc.) v_mom_adv_order= 3, vertical momentum advection order h_sca_adv_order= 5, horizontal scalar advection order v_sca_adv_order= 3, vertical scalar advection order io_form = 1, (not active) = 2, NetCDF format Description of namelist_04

21. &namelist_05 start_year = 2000, four digit year of starting time start_month= 11, two digit (01-12) month of starting time start_day = 20, two digit (01-31) day of starting time start_hour = 12, two digit (00-23) hour of starting time start_minute= 00, two digit (00-59) minute of starting time start_second= 00, two digit (00-59) second of starting time end_year = 2000, four digit year of ending time end_month = 11, two digit (01-12) month of ending time end_day = 21, two digit (01-31) day of ending time end_hour = 00, two digit (00-23) hour of ending time end_minute = 00, two digit (00-59) minute of ending time end_second = 00, two digit (00-59) second of ending time interval_seconds= 43200, time interval in seconds between analysis (and boundary) times Description of namelist_05

22. real_data_init_type which type of real input: = 1, WRF SI = 2, MM5 = 3, user written routine read_generic in module_si_io.F Description of namelist_05

23. WRF input files n Running real.exe turns wrf_input.d01.yyyy-mm-dd_hh:mm:ss to wrfinput and wrfbdy

24. WRF output files n After one runs wrf.exe, WRf produces these output files: wrfout_01_000000: history file wrfrst_01_nnnnnn: restart file where nnnnnn is model time step If one splits output files, one may obtain: wrfout_01_xxxxxx where xxxxxx is the time step at which the output file is written.