Description of namelist variables --------------------------------- For WRF-NMM users, please see Chapter 5 of the WRF-NMM User's Guide for information on NMM specific settings (http://www.dtcenter.org/wrf-nmm/users) Note: variables followed by (max_dom) indicate that this variable needs to be defined for the nests when max_dom > 1. &time_control run_days = 1, ; run time in days run_hours = 0, ; run time in hours Note: if it is more than 1 day, one may use both run_days and run_hours or just run_hours. e.g. if the total run length is 36 hrs, you may set run_days = 1, and run_hours = 12, or run_days = 0, and run_hours = 36 run_minutes = 0, ; run time in minutes run_seconds = 0, ; run time in seconds start_year (max_dom) = 2001, ; four digit year of starting time start_month (max_dom) = 06, ; two digit month of starting time start_day (max_dom) = 11, ; two digit day of starting time start_hour (max_dom) = 12, ; two digit hour of starting time start_minute (max_dom) = 00, ; two digit minute of starting time start_second (max_dom) = 00, ; two digit second of starting time Note: the start time is used to name the first wrfout file. It also controls the start time for nest domains, and the time to restart tstart (max_dom) = 00, ; FOR NMM: starting hour of the forecast end_year (max_dom) = 2001, ; four digit year of ending time end_month (max_dom) = 06, ; two digit month of ending time end_day (max_dom) = 12, ; two digit day of ending time end_hour (max_dom) = 12, ; two digit hour of ending time end_minute (max_dom) = 00, ; two digit minute of ending time end_second (max_dom) = 00, ; two digit second of ending time It also controls when the nest domain integrations end All start and end times are used by real.exe. Note that one may use either run_days/run_hours etc. or end_year/month/day/hour etc. to control the length of model integration. But run_days/run_hours takes precedence over the end times. Program real.exe uses start and end times only. interval_seconds = 10800, ; time interval between incoming real data, which will be the interval between the lateral boundary condition file input_from_file (max_dom) = T, ; whether nested run will have input files for domains other than 1 fine_input_stream (max_dom) = 0, ; field selection from nest input for its initialization 0: all fields are used; 2: only static and time-varying, masked land surface fields are used. history_interval (max_dom) = 60, ; history output file interval in minutes frames_per_outfile (max_dom) = 1, ; output times per history output file, used to split output files into smaller pieces restart = F, ; whether this run is a restart run restart_interval = 1440, ; restart output file interval in minutes io_form_history = 2, ; 2 = netCDF io_form_restart = 2, ; 2 = netCDF io_form_input = 2, ; 2 = netCDF io_form_boundary = 2, ; netCDF format = 4, ; PHD5 format = 5, ; GRIB1 format frames_per_emissfile = 12, ; Number of times in each chemistry emission file. io_style_emiss = 1, ; Style to use for the chemistry emission files. ; 0 = Do not read emissions from files. ; 1 = Cycle between two 12 hour files (set frames_per_emissfile=12) ; 2 = Dated files with length set by frames_per_emissfile debug_level = 0, ; 50,100,200,300 values give increasing prints To choose between SI and WPS input to real: auxinput1_inname = "met_em.d." ; Input to real from WPS = "wrf_real_input_em.d." ; Input to real from SI Other output options: auxhist2_outname = "rainfall" ; file name for extra output; if not specified, auxhist2_d_ will be used also note that to write variables in output other than the history file requires Registry.EM file change auxhist2_interval (max_dom) = 10, ; interval in minutes io_form_auxhist2 = 2, ; output in netCDF Additional ones when running 3DVAR: write_input = t, ; write input-formatted data as output inputout_interval = 180, ; interval in minutes when writing input-formatted data input_outname = 'wrf_3dvar_input_d_' ; you may change the output file name inputout_begin_y = 0 inputout_begin_mo = 0 inputout_begin_d = 0 inputout_begin_h = 3 inputout_begin_m = 0 inputout_begin_s = 0 inputout_end_y = 0 inputout_end_mo = 0 inputout_end_d = 0 inputout_end_h = 12 inputout_end_m = 0 inputout_end_s = 0 ; the above shows that the input-formatted data are output starting from hour 3 to hour 12 in 180 min interval. &domains time_step = 60, ; time step for integration in integer seconds recommend 6*dx (in km) for typical real-data cases time_step_fract_num = 0, ; numerator for fractional time step time_step_fract_den = 1, ; denominator for fractional time step Example, if you want to use 60.3 sec as your time step, set time_step = 60, time_step_fract_num = 3, and time_step_fract_den = 10 max_dom = 1, ; number of domains - set it to > 1 if it is a nested run s_we (max_dom) = 1, ; start index in x (west-east) direction (leave as is) e_we (max_dom) = 91, ; end index in x (west-east) direction (staggered dimension) s_sn (max_dom) = 1, ; start index in y (south-north) direction (leave as is) e_sn (max_dom) = 82, ; end index in y (south-north) direction (staggered dimension) s_vert (max_dom) = 1, ; start index in z (vertical) direction (leave as is) e_vert (max_dom) = 28, ; end index in z (vertical) direction (staggered dimension) Note: this refers to full levels including surface and top vertical dimensions need to be the same for all nests Note: most variables are unstaggered (= staggered dim - 1) dx (max_dom) = 10000, ; grid length in x direction, unit in meters dy (max_dom) = 10000, ; grid length in y direction, unit in meters ztop (max_dom) = 19000. ; used in mass model for idealized cases grid_id (max_dom) = 1, ; domain identifier parent_id (max_dom) = 0, ; id of the parent domain i_parent_start (max_dom) = 0, ; starting LLC I-indices from the parent domain j_parent_start (max_dom) = 0, ; starting LLC J-indices from the parent domain parent_grid_ratio (max_dom) = 1, ; parent-to-nest domain grid size ratio: for real-data cases the ratio has to be odd; for idealized cases, the ratio can be even if feedback is set to 0. parent_time_step_ratio (max_dom) = 1, ; parent-to-nest time step ratio; it can be different from the parent_grid_ratio feedback = 1, ; feedback from nest to its parent domain; 0 = no feedback smooth_option = 0 ; smoothing option for parent domain, used only with feedback option on. 0: no smoothing; 1: 1-2-1 smoothing; 2: smoothing-desmoothing Namelist variables specifically for the WPS input for real: num_metgrid_levels = 27 ; number of vertical levels of 3d meteorological fields coming ; from WPS metgrid program interp_type = 1 ; vertical interpolation ; 1 = linear in pressure ; 2 = linear in log(pressure) lagrange_order = 1 ; vertical interpolation order ; 1 = linear ; 2 = quadratic zap_close_levels = 500 ; ignore isobaric level above surface if delta p (Pa) < zap_close_levels lowest_lev_from_sfc = .false. ; place the surface value into the lowest eta location ; T = use surface value as lowest eta (u,v,t,q) ; F = use traditional interpolation force_sfc_in_vinterp = 1 ; use the surface level as the lower boundary when interpolating ; through this many eta levels ; 0 = perform traditional trapping interpolation ; n = first n eta levels directly use surface level p_top_requested = 5000 ; p_top (Pa) to use in the model Users may explicitly define full eta levels. Given are two distributions for 28 and 35 levels. The number of levels must agree with the number of eta surfaces allocated (e_vert). Users may alternatively request only the number of levels (with e_vert), and the real program will compute values. The computation assumes a known first several layers, then generates equi-height spaced levels up to the top of the model. eta_levels = 1.000, 0.990, 0.978, 0.964, 0.946, 0.922, 0.894, 0.860, 0.817, 0.766, 0.707, 0.644, 0.576, 0.507, 0.444, 0.380, 0.324, 0.273, 0.228, 0.188, 0.152, 0.121, 0.093, 0.069, 0.048, 0.029, 0.014, 0.000, eta_levels = 1.000, 0.993, 0.983, 0.970, 0.954, 0.934, 0.909, 0.880, 0.845, 0.807, 0.765, 0.719, 0.672, 0.622, 0.571, 0.520, 0.468, 0.420, 0.376, 0.335, 0.298, 0.263, 0.231, 0.202, 0.175, 0.150, 0.127, 0.106, 0.088, 0.070, 0.055, 0.040, 0.026, 0.013, 0.000 Namelist variables for controling the specified moving nest: Note that this moving nest option needs to be activated at the compile time by adding -DMOVE_NESTS to the ARCHFLAGS. The maximum number of moves, max_moves, is set to 50 but can be modified in source code file frame/module_driver_constants.F. num_moves = 4 ; total number of moves move_id = 2,2,2,2, ; a list of nest domain id's, one per move move_interval = 60,120,150,180, ; time in minutes since the start of this domain move_cd_x = 1,1,0,-1,; the number of parent domain grid cells to move in i direction move_cd_y = 1,0,-1,1,; the number of parent domain grid cells to move in j direction positive is to move in increasing i and j direction, and negative is to move in decreasing i and j direction. 0 means no move. The limitation now is to move only 1 grid cell at each move. Namelist variables for controling the automatic moving nest: Note that this moving nest option needs to be activated at the compile time by adding -DMOVE_NESTS and -DVORTEX_CENTER to the ARCHFLAGS. This option uses an mid-level vortex following algorthm to determine the nest move. This option is experimental. vortex_interval = 15 ; how often the new vortex position is computed max_vortex_speed = 40 ; used to compute the search radius for the new vortex position corral_dist = 8 ; how many coarse grid cells the moving nest is allowed to get near the mother domain boundary &physics Note: even the physics options can be different in different nest domains, caution must be used as what options are sensible to use chem_opt = 0, ; chemistry option - not yet available mp_physics (max_dom) microphysics option = 0, no microphysics = 1, Kessler scheme = 2, Lin et al. scheme = 3, WSM 3-class simple ice scheme = 4, WSM 5-class scheme = 5, Ferrier (new Eta) microphysics = 6, WSM 6-class graupel scheme = 8, Thompson et al. scheme = 98, NCEP 3-class simple ice scheme (to be removed) = 99, NCEP 5-class scheme (to be removed) For non-zero mp_physics options, to keep Qv .GE. 0, and to set the other moisture fields .LT. a critcal value to zero mp_zero_out = 0, ; no action taken, no adjustment to any moist field = 1, ; except for Qv, all other moist arrays are set to zero ; if they fall below a critical value = 2, ; Qv is .GE. 0, all other moist arrays are set to zero ; if they fall below a critical value mp_zero_out_thresh = 1.e-8 ; critical value for moist array threshold, below which ; moist arrays (except for Qv) are set to zero (kg/kg) ra_lw_physics (max_dom) longwave radiation option = 0, no longwave radiation = 1, rrtm scheme = 3, cam scheme also must set levsiz, paerlev, cam_abs_dim1/2 (see below) = 99, GFDL (Eta) longwave (semi-supported) also must use co2tf = 1 for ARW ra_sw_physics (max_dom) shortwave radiation option = 0, no shortwave radiation = 1, Dudhia scheme = 2, Goddard short wave = 3, cam scheme also must set levsiz, paerlev, cam_abs_dim1/2 (see below) = 99, GFDL (Eta) longwave (semi-supported) also must use co2tf = 1 for ARW radt (max_dom) = 30, ; minutes between radiation physics calls recommend 1 min per km of dx (e.g. 10 for 10 km) nrads (max_dom) = FOR NMM: number of fundamental timesteps between calls to shortwave radiation; the value is set in Registry.NMM but is overridden by namelist value; radt will be computed from this. nradl (max_dom) = FOR NMM: number of fundamental timesteps between calls to longwave radiation; the value is set in Registry.NMM but is overridden by namelist value. co2tf CO2 transmission function flag only for GFDL radiation = 0, read CO2 function data from pre-generated file = 1, generate CO2 functions internally in the forecast ra_call_offset radiation call offset = 0 (no offset), =-1 (old offset) cam_abs_freq_s = 21600 CAM clearsky longwave absorption calculation frequency (recommended minimum value to speed scheme up) levsiz = 59 for CAM radiation input ozone levels paerlev = 29 for CAM radiation input aerosol levels cam_abs_dim1 = 4 for CAM absorption save array cam_abs_dim2 = e_vert for CAM 2nd absorption save array sf_sfclay_physics (max_dom) surface-layer option (old bl_sfclay_physics option) = 0, no surface-layer = 1, Monin-Obukhov scheme = 2, Monin-Obukhov (Janjic) scheme = 3, NCEP Global Forecast System scheme sf_surface_physics (max_dom) land-surface option (old bl_surface_physics option) = 0, no surface temp prediction = 1, thermal diffusion scheme = 2, Noah land-surface model = 3, RUC land-surface model bl_pbl_physics (max_dom) boundary-layer option = 0, no boundary-layer = 1, YSU scheme = 2, Mellor-Yamada-Janjic TKE scheme = 3, NCEP Global Forecast System scheme = 99, MRF scheme (to be removed) bldt (max_dom) = 0, ; minutes between boundary-layer physics calls nphs (max_dom) = FOR NMM: number of fundamental timesteps between calls to turbulence and microphysics; the value is set in Registry.NMM but is overridden by namelist value; bldt will be computed from this. cu_physics (max_dom) cumulus option = 0, no cumulus = 1, Kain-Fritsch (new Eta) scheme = 2, Betts-Miller-Janjic scheme = 3, Grell-Devenyi ensemble scheme = 4, Simplified Arakawa-Schubert scheme = 99, previous Kain-Fritsch scheme cudt = 0, ; minutes between cumulus physics calls ncnvc (max_dom) = FOR NMM: number of fundamental timesteps between calls to convection; the value is set in Registry.NMM but is overridden by namelist value; cudt will be computed from this. tprec (max_dom) = FOR NMM: number of hours in precipitation bucket theat (max_dom) = FOR NMM: number of hours in latent heating bucket tclod (max_dom) = FOR NMM: number of hours in cloud fraction average trdsw (max_dom) = FOR NMM: number of hours in short wave buckets trdlw (max_dom) = FOR NMM: number of hours in long wave buckets tsrfc (max_dom) = FOR NMM: number of hours in surface flux buckets pcpflg (max_dom) = FOR NMM: logical switch for precipitation assimilation isfflx = 1, ; heat and moisture fluxes from the surface (only works for sf_sfclay_physics = 1) 1 = with fluxes from the surface 0 = no flux from the surface ifsnow = 0, ; snow-cover effects (only works for sf_surface_physics = 1) 1 = with snow-cover effect 0 = without snow-cover effect icloud = 1, ; cloud effect to the optical depth in radiation (only works for ra_sw_physics = 1 and ra_lw_physics = 1) 1 = with cloud effect 0 = without cloud effect swrad_scat = 1. ; scattering tuning parameter (default 1. is 1.e-5 m2/kg) surface_input_source = 1, ; where landuse and soil category data come from: 1 = SI/gridgen 2 = GRIB data from another model (only possible (VEGCAT/SOILCAT are in wrf_real_input_em files from SI) num_soil_layers = 5, ; number of soil layers in land surface model = 5: thermal diffusion scheme = 4: Noah landsurface model = 6: RUC landsurface model ucmcall = 0, ; activate urban canopy model (in Noah LSM only) (0=no, 1=yes) maxiens = 1, ; Grell-Devenyi only maxens = 3, ; G-D only maxens2 = 3, ; G-D only maxens3 = 16 ; G-D only ensdim = 144 ; G-D only These are recommended numbers. If you would like to use any other number, consult the code, know what you are doing. seaice_threshold = 271 ; tsk < seaice_threshold, if water point and 5-layer slab ; scheme, set to land point and permanent ice; if water point ; and Noah scheme, set to land point, permanent ice, set temps ; from 3 m to surface, and set smois and sh2o sst_update = 0 ; time-varying sea-surface temp (0=no, 1=yes). If selected real ; puts SST and VEGFRA in wrflowinp_d01 file, and wrf updates these from it ; at same interval as boundary file. To read this, the time-control ; namelist must include auxinput5_interval, auxinput5_end_h, and ; auxinput5_inname = "wrflowinp_d" &fdda grid_fdda (max_dom) = 1 ; grid-nudging fdda on (=0 off) for each domain gfdda_inname = "wrffdda_d" ; defined name in real gfdda_interval_m (max_dom) = 360 ; time interval (min) between analysis times gfdda_end_h (max_dom) = 6 ; time (h) to stop nudging after start of forecast io_form_gfdda = 2 ; analysis data io format (2 = netCDF) fgdt (max_dom) = 0 ; calculation frequency (minutes) for grid-nudging (0=every step) if_no_pbl_nudging_uv (max_dom) = 0 ; 0= no nudging of u and v in the pbl, 1=nudging in the pbl if_no_pbl_nudging_t (max_dom) = 0 ; 0= no nudging of temp in the pbl, 1=nudging in the pbl if_no_pbl_nudging_q (max_dom) = 0 ; 0= no nudging of qvapor in the pbl, 1=nudging in the pbl if_zfac_uv (max_dom) = 0 ; 0= nudge u and v all layers, 1= limit nudging to levels above k_zfac_uv k_zfac_uv (max_dom) = 10 ; 10=model level below which nudging is switched off for u and v if_zfac_t (max_dom) = 0 ; 0= nudge temp all layers, 1= limit nudging to levels above k_zfac_t k_zfac_t (max_dom) = 10 ; 10=model level below which nudging is switched off for temp if_zfac_q (max_dom) = 0 ; 0= nudge qvapor all layers, 1= limit nudging to levels above k_zfac_q k_zfac_q (max_dom) = 10 ; 10=model level below which nudging is switched off for qvapor guv (max_dom) = 0.0003 ; nudging coefficient for u and v (sec-1) gt (max_dom) = 0.0003 ; nudging coefficient for temp (sec-1) gq (max_dom) = 0.0003 ; nudging coefficient for qvapor (sec-1) if_ramping = 0 ; 0= nudging ends as a step function, 1= ramping nudging down at end of period dtramp_min = 60.0 ; time (min) for ramping function, 60.0=ramping starts at last analysis time, -60.0=ramping ends at last analysis time The following are for observation nudging: obs_nudge_opt (max_dom) = 1 ; obs-nudging fdda on (=0 off) for each domain also need to set auxinput11_interval and auxinput11_end_h in time_control namelist max_obs = 150000 ; max number of observations used on a domain during any given time window fdda_start = 0 ; obs nudging start time in minutes fdda_end = 180 ; obs nudging end time in minutes obs_nudge_wind (max_dom) = 1 ; whether to nudge wind: (=0 off) obs_coef_wind = 6.E-4, ; nudging coefficient for wind, unit: s-1 obs_nudge_temp = 1 ; whether to nudge temperature: (=0 off) obs_coef_temp = 6.E-4, ; nudging coefficient for temperature, unit: s-1 obs_nudge_mois = 1 ; whether to nudge water vapor mixing ratio: (=0 off) obs_coef_mois = 6.E-4, ; nudging coefficient for water vapor mixing ratio, unit: s-1 obs_nudge_pstr = 0 ; whether to nudge surface pressure (not used) obs_coef_pstr = 0. ; nudging coefficient for surface pressure, unit: s-1 (not used) obs_rinxy = 200., ; horizonal radius of influence in km obs_rinsig = 0.1, ; vertical radius of influence in eta obs_twindo = 40, ; half-period time window over which an observation will be used for nudging obs_npfi = 10, ; freq in coarse grid timesteps for diag prints obs_ionf = 2 ; freq in coarse grid timesteps for obs input and err calc obs_idynin = 0 ; for dynamic initialization using a ramp-down function to gradually turn off the FDDA before the pure forecast (=1 on) obs_dtramp = 40 ; time period in minutes over which the nudging is ramped down from one to zero. obs_ipf_in4dob = .true. ; print obs input diagnostics (=.false. off) obs_ipf_errob = .true. ; print obs error diagnostics (=.false. off) obs_ipf_nudob = .true. ; print obs nudge diagnostics (=.false. off) / &dynamics dyn_opt = 2, ; dynamical core option: advanced research WRF core (Eulerian mass) rk_ord = 3, ; time-integration scheme option: 2 = Runge-Kutta 2nd order 3 = Runge-Kutta 3rd order diff_opt = 0, ; turbulence and mixing option: 0 = no turbulence or explicit spatial numerical filters (km_opt IS IGNORED). 1 = evaluates 2nd order diffusion term on coordinate surfaces. uses kvdif for vertical diff unless PBL option is used. may be used with km_opt = 1 and 4. (= 1, recommended for real-data case when grid distance < 10 km) 2 = evaluates mixing terms in physical space (stress form) (x,y,z). turbulence parameterization is chosen by specifying km_opt. km_opt = 1, ; eddy coefficient option 1 = constant (use khdif kvdif) 2 = 1.5 order TKE closure (3D) 3 = Smagorinsky first order closure (3D) Note: option 2 and 3 are not recommended for DX > 2 km 4 = horizontal Smagorinsky first order closure (recommended for real-data case when grid distance < 10 km) damp_opt = 0, ; upper level damping flag 0 = without damping 1 = with diffusive damping, maybe used for real-data cases (dampcoef nondimensional ~0.01-0.1) 2 = with Rayleigh damping (dampcoef inverse time scale [1/s] e.g. .003; not for real-data cases) diff_6th_opt = 0, ; 6th-order numerical diffusion 0 = no 6th-order diffusion (default) 1 = 6th-order numerical diffusion 2 = 6th-order numerical diffusion but prohibit up-gradient diffusion diff_6th_factor = 0.12, ; 6th-order numerical diffusion non-dimensional rate (max value 1.0 corresponds to complete removal of 2dx wave in one timestep) dampcoef (max_dom) = 0., ; damping coefficient (see above) zdamp (max_dom) = 5000., ; damping depth (m) from model top w_damping = 0, ; vertical velocity damping flag (for operational use) 0 = without damping 1 = with damping base_temp = 290., ; real-data, em ONLY, base sea-level temp (K) base_pres = 10^5 ; real-data, em ONLY, base sea-level pres (Pa), DO NOT CHANGE base_lapse = 50., ; real-data, em ONLY, lapse rate (K), DO NOT CHANGE khdif (max_dom) = 0, ; horizontal diffusion constant (m^2/s) kvdif (max_dom) = 0, ; vertical diffusion constant (m^2/s) smdiv (max_dom) = 0.1, ; divergence damping (0.1 is typical) emdiv (max_dom) = 0.01, ; external-mode filter coef for mass coordinate model (0.01 is typical for real-data cases) epssm (max_dom) = .1, ; time off-centering for vertical sound waves non_hydrostatic (max_dom) = .true., ; whether running the model in hydrostatic or non-hydro mode pert_coriolis (max_dom) = .false., ; Coriolis only acts on wind perturbation (idealized) mix_full_fields(max_dom) = .true., ; used with diff_opt = 2; value of ".true." is recommended, except for highly idealized numerical tests; damp_opt must not be 1 if ".true." is chosen. .false. means subtract 1-d base-state profile before mixing tke_drag_coefficient(max_dom) = 0., ; surface drag coefficient (Cd, dimensionless) for diff_opt=2 only tke_heat_flux(max_dom) = 0., ; surface thermal flux (H/(rho*cp), K m/s) for diff_opt=2 only h_mom_adv_order (max_dom) = 5, ; horizontal momentum advection order (5=5th, etc.) v_mom_adv_order (max_dom) = 3, ; vertical momentum advection order h_sca_adv_order (max_dom) = 5, ; horizontal scalar advection order v_sca_adv_order (max_dom) = 3, ; vertical scalar advection order pd_moist = F ; positive definite advection of moisture pd_scalar = F ; positive definite advection of scalars pd_chem = F ; positive definite advection of chem variables pd_tke = F ; positive definite advection of tke time_step_sound (max_dom) = 4 / ; number of sound steps per time-step (0=set automatically) (if using a time_step much larger than 6*dx (in km), proportionally increase number of sound steps - also best to use even numbers) &bdy_control spec_bdy_width = 5, ; total 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) specified (max_dom) = .false., ; specified boundary conditions (only for domain 1) the above 4 are used for real-data runs periodic_x (max_dom) = .false., ; periodic boundary conditions in x direction symmetric_xs (max_dom) = .false., ; symmetric boundary conditions at x start (west) symmetric_xe (max_dom) = .false., ; symmetric boundary conditions at x end (east) open_xs (max_dom) = .false., ; open boundary conditions at x start (west) open_xe (max_dom) = .false., ; open boundary conditions at x end (east) periodic_y (max_dom) = .false., ; periodic boundary conditions in y direction symmetric_ys (max_dom) = .false., ; symmetric boundary conditions at y start (south) symmetric_ye (max_dom) = .false., ; symmetric boundary conditions at y end (north) open_ys (max_dom) = .false., ; open boundary conditions at y start (south) open_ye (max_dom) = .false., ; open boundary conditions at y end (north) nested (max_dom) = .false., ; nested boundary conditions (inactive) &namelist_quilt This namelist record controls asynchronized I/O for MPI applications. nio_tasks_per_group = 0, default value is 0: no quilting; > 0 quilting I/O nio_groups = 1, default 1, don't change miscelleneous in &domains: tile_sz_x = 0, ; number of points in tile x direction tile_sz_y = 0, ; number of points in tile y direction can be determined automatically numtiles = 1, ; number of tiles per patch (alternative to above two items) nproc_x = -1, ; number of processors in x for decomposition nproc_y = -1, ; number of processors in y for decomposition -1: code will do automatic decomposition >1: for both: will be used for decomposition