[Wrf-users] Fwd: two way nest run crashes without errors

[Xin Xi]

Thanks Eric! I will look into using 3 nests.
Just to clarify, if I use time step of 60sec for parent domain and
parent_time_step_ratio of 6, the nest domain will run at 10sec, correct? I
suspect a small time step (like 10 sec) is needed for such fine resolution
domain (e.g. 1km). Why did you say that would make the time step too large
on the nest domain?


On Mon, Jun 9, 2014 at 1:10 PM, Eric Altshuler <ela at cola.iges.org> wrote:

> I would think a nest grid ratio of 15 is too large. The recommended value
> is 3, and 5 can also be used. Also, your time step ratio is 6, which would
> probably make the time step too large on your nest domain with a grid ratio
> of 15. You need to use a triple nest if your high resolution domain is 1
> km. One suggestion might be:
>
> dx = 15000, 5000, 1000
> dy = 15000, 5000, 1000
> parent_grid_ratio = 1, 3, 5
> parent_time_step_ratio = 1, 3, 5
>
> or:
>
> dx = 15000, 3000, 1000
> dy = 15000, 3000, 1000
> parent_grid_ratio = 1, 5, 3
> parent_time_step_ratio = 1, 5, 3
>
> I'm not sure which one is preferable.
>
> Best regards,
>
>
>
> Eric L. Altshuler
> Research Scientist
> Center for Ocean-Land-Atmosphere Studies
> 253 Research Hall, Mail Stop 6C5
> George Mason University
> 4400 University Drive
> Fairfax, VA 22030 USA
>
> E-mail: ela at cola.iges.org
> Phone: (703) 993-5725
> Fax: (703) 993-5770
>
>
> ------------------------------
> *From: *"Xin Xi" <xxi at gatech.edu>
> *To: *wrf-users at ucar.edu
> *Sent: *Monday, June 9, 2014 11:12:26 AM
> *Subject: *[Wrf-users] Fwd: two way nest run crashes without errors
>
> Hi I am running wrf 3.6 with two way nesting. After the spinning up on
> outer domain, the program stopped without any warning or errors. in other
> words, the program simply stopped at the beginning of the nest domain start
> time. I wonder whether this is an issue of parent_grid_ratio (=15), time
> step or the vertical lvls. Please help. Thanks.
>
>  Here is excerpt of namelist.input:
>
>  &time_control
>  run_days                            = 3,
>  run_hours                           = 13,
>  run_minutes                         = 0,
>  run_seconds                         = 0,
>  start_year                          = 2013, 2013, 2000,
>  start_month                         = 03,   03,   01,
>  start_day                           = 10,   11,   24,
>  start_hour                          = 12,   00,   12,
>  start_minute                        = 00,   00,   00,
>  start_second                        = 00,   00,   00,
>  end_year                            = 2013, 2013, 2000,
>  end_month                           = 03,   03,   01,
>  end_day                             = 14,   14,   25,
>  end_hour                            = 00,   00,   12,
>  end_minute                          = 00,   00,   00,
>  end_second                          = 00,   00,   00,
>  interval_seconds                    = 21600
>  input_from_file                     = .true.,.true.,.true.,
>  history_interval                    = 60,  60,   60,
>  frames_per_outfile                  = 24, 24, 1000,
>  restart                             = .false.,
>  restart_interval                    = 5000,
>  io_form_history                     = 2
>  io_form_restart                     = 2
>  io_form_input                       = 2
>  io_form_boundary                    = 2
>  debug_level                         = 5000
>  fine_input_stream                   = 0, 2, 2,
>  io_form_auxinput2                   = 2
>  /
>
>  &domains
>  time_step                           = 60,
>  time_step_fract_num                 = 0,
>  time_step_fract_den                 = 1,
>  max_dom                             = 2,
>  e_we                                = 50,    166,   94,
>  e_sn                                = 50,    166,    91,
>  e_vert                              = 57,    57,    30,
>  p_top_requested                     = 5000,
>  num_metgrid_levels                  = 27,
>  num_metgrid_soil_levels             = 4,
>  dx                                  = 15000, 1000,  3333.33,
>  dy                                  = 15000, 1000,  3333.33,
>  grid_id                             = 1,     2,     3,
>  parent_id                           = 0,     1,     2,
>  i_parent_start                      = 1,     20,    30,
>  j_parent_start                      = 1,     20,    30,
>  parent_grid_ratio                   = 1,     15,     3,
>  parent_time_step_ratio              = 1,     6,     3,
>  feedback                            = 1,
>  smooth_option                       = 0,
>  eta_levels                          = 1.000, 0.999, 0.998, 0.997, 0.996,
> 0.995, 0.994, 0.993,
>                                        0.991, 0.988, 0.985, 0.982, 0.978,
> 0.974, 0.970, 0.965,
>                                        0.960, 0.955, 0.950, 0.945, 0.935,
> 0.925, 0.915, 0.905,
>                                        0.895, 0.875, 0.855, 0.840, 0.820,
> 0.800, 0.760, 0.720,
>                                        0.680, 0.640, 0.600, 0.575, 0.525,
> 0.485, 0.445, 0.400,
>                                        0.350, 0.300, 0.285, 0.251, 0.217,
> 0.192, 0.164, 0.141,
>                                        0.119, 0.103, 0.083, 0.067, 0.055,
> 0.043, 0.033, 0.024,
>                                        0.000,
>
>  /
>
>
>
>
> --
>
>
>
> *Xin XiSchool of Earth and Atmospheric SciencesGeorgia Institute of
> Technology311 Ferst Drive, Atlanta, GA 30332-0340*
>
> _______________________________________________
> Wrf-users mailing list
> Wrf-users at ucar.edu
> http://mailman.ucar.edu/mailman/listinfo/wrf-users
>



-- 



*Xin XiSchool of Earth and Atmospheric SciencesGeorgia Institute of
Technology311 Ferst Drive, Atlanta, GA 30332-0340*
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