CFL=2 when using Thompson microphysics

Any issues with the actual running of the WRF.

CFL=2 when using Thompson microphysics

Postby kimispa » Mon Mar 26, 2018 4:37 am

Dear all,
I am running WRF and finding cfl=2 when I use mp8 (Thomposon scheme) as the mocrophysical scheme. The run is completed with this namelist.

WRF TILE 1 IS 385 IE 432 JS 1 JE 30
WRF NUMBER OF TILES = 1
d01 2018-03-27_07:49:20 1 points exceeded cfl=2 in domain d01 at tim
e 2018-03-27_07:49:20 hours
d01 2018-03-27_07:49:20 MAX AT i,j,k: 408 27 21 ver
t_cfl,w,d(eta)= 2.064706 -2.115188 3.6760032E-02
d01 2018-03-27_07:52:00 1 points exceeded cfl=2 in domain d01 at tim
e 2018-03-27_07:52:00 hours
d01 2018-03-27_07:52:00 MAX AT i,j,k: 408 27 20 ver
t_cfl,w,d(eta)= 2.192773 -10.02741 3.8659990E-02
d01 2018-03-27_07:53:20 10 points exceeded cfl=2 in domain d01 at tim
e 2018-03-27_07:53:20 hours
d01 2018-03-27_07:53:20 MAX AT i,j,k: 408 27 28 ver
t_cfl,w,d(eta)= 2.157542 8.741779 2.5429994E-02
d01 2018-03-27_07:56:00 9 points exceeded cfl=2 in domain d01 at tim
e 2018-03-27_07:56:00 hours
d01 2018-03-27_07:56:00 MAX AT i,j,k: 408 27 33 ver
t_cfl,w,d(eta)= 2.105193 10.30213 1.9209996E-02

Namelist:

&time_control
run_days = 0,
run_hours = 96,
run_minutes = 0,
run_seconds = 0,
start_year = 2018, 2018, 2018,
start_month = 03, 03, 03,
start_day = 25, 25, 25,
start_hour = 12, 12, 12,
start_minute = 00, 00, 00,
start_second = 00, 00, 00,
end_year = 2018, 2018, 2018,
end_month = 03, 03, 03,
end_day = 29, 29, 29,
end_hour = 12, 12, 12,
end_minute = 00, 00, 00,
end_second = 00, 00, 00,
interval_seconds = 10800,
input_from_file = .false.,.true.,.true.,
history_interval = 60, 60, 60,
frames_per_outfile = 1, 1, 1000,
restart = .false.,
restart_interval = 5000,
io_form_history = 2
io_form_restart = 2
io_form_input = 2
io_form_boundary = 2
write_input = .false.
inputout_interval = 60,
input_outname = "wrfvar_input_d<domain>_<date>",
inputout_begin_y = 0,
inputout_begin_d = 0,
inputout_begin_h = 0,
inputout_begin_m = 0,
inputout_begin_s = 0,
inputout_end_y = 0,
inputout_end_d = 0,
inputout_end_h = 72,
inputout_end_m = 0,
inputout_end_s = 0,
debug_level =0
/

&domains
time_step = 80
time_step_fract_num = 0,
time_step_fract_den = 1,
max_dom = 1,
e_we = 481, 271, 94,
e_sn = 361, 241, 91,
e_vert = 51, 51, 51,
p_top_requested = 5000
eta_levels = 1.00000,0.99381,0.98643,0.97786,0.96815,0.95731,0.94538,0.93122,0.91490,0.89653,0.87621,0.85405,0.82911,0.80160,0.77175,0.73981,0.70509,0.66798,0.62889,0.58823,0.54957,0.51281,0.47788,0.44471,0.41323,0.38336,0.35503,0.32819,0.30276,0.27869,0.25592,0.23439,0.21405,0.19484,0.17672,0.15963,0.14352,0.12836,0.11410,0.10070,0.08811,0.07630,0.06523,0.05487,0.04517,0.03611,0.02765,0.01977,0.01243,0.00560,0.00000,
interp_type = 2
num_metgrid_levels = 32
num_metgrid_soil_levels = 4,
dx = 15000, 3000, 3333.33,
dy = 15000, 3000, 3333.33,
grid_id = 1, 2, 3,
parent_id = 0, 1, 2,
i_parent_start = 1, 285, 30,
j_parent_start = 1, 148, 30,
parent_grid_ratio = 1, 5, 3,
parent_time_step_ratio = 1, 5, 3,
feedback = 0,
smooth_option = 0
force_sfc_in_vinterp = 1,
hypsometric_opt = 2,
/

&physics
mp_physics = 8, 8, 8,
ra_lw_physics = 1, 1, 1,
ra_sw_physics = 2, 2, 2,
radt = 30, 30,
sf_sfclay_physics = 1, 1, 1,
sf_surface_physics = 2, 2, 2,
bl_pbl_physics = 1, 1, 1,
bldt = 0, 0,
sf_urban_physics =1, 1,
cu_physics = 1, 1, 1,
kfeta_trigger = 2
cudt = 0, 0,
isfflx = 1,
ifsnow = 1,
icloud = 1,
num_soil_layers = 4,
num_land_cat = 24,
mp_zero_out = 0,
mp_zero_out_thresh = 1.e-8,
maxiens = 1,
maxens = 3,
maxens2 = 3,
maxens3 = 16,
ensdim = 144,
mfshconv = 0,
/

&fdda
/

&dynamics
w_damping = 1,
diff_opt = 1,
km_opt = 4,
diff_6th_opt = 0,
diff_6th_factor = 0.12,
base_temp = 290.
damp_opt = 3,
gwd_opt = 1,
zdamp = 5000., 5000.,
dampcoef = .2, 0.2
khdif = 0, 0,
kvdif = 0, 0,
non_hydrostatic = .true., .true.,
moist_adv_opt = 1, 1,
scalar_adv_opt = 0, 0,
/

&bdy_control
spec_bdy_width = 5,
spec_zone = 1,
relax_zone = 4,
specified = .true., .false.,
nested = .false., .true.,
/

&grib2
/

&namelist_quilt
nio_tasks_per_group = 0,
nio_groups = 1,
/

&dfi_control
/

I have done more test: (1) the time step is decreased from 80s to 75s, the cfl problem also arises.
(2) The microphysics scheme is changed from Thomposon to WSM6, the WRF forecast can be run successfully.


Why could this be happening when the Thomposon scheme is used?
Can anyone help me with this.

Thank you so much in advance.
kimispa
 
Posts: 1
Joined: Tue Jun 12, 2012 12:01 am

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