lightning flash counts values shows always zero in WRF output

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srinivas nekkali

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Jun 21, 2021, 12:43:59 AM6/21/21

to wrf-chem-lightning

Dear all,
I am trying to simulate the Lightning Flashcount of ESCS cyclone over the Indian Ocean region (without chemistry) and its related namelist attached below. But, in the output, I got zero values for both IC and GC Flash counts. Why it's happened? I did any mistake? Please provide your valuable suggestions and help.

&time_control

!run_days = 0,

!run_hours = 12,

!run_minutes = 0,

!run_seconds = 0,

start_year = 2019, 2000, 2000,

start_month = 04, 01, 01,

start_day = 29, 24, 24,

start_hour = 00, 12, 12,

start_minute = 00, 00, 00,

start_second = 00, 00, 00,

end_year = 2019, 2000, 2000,

end_month = 05, 01, 01,

end_day = 02, 25, 25,

end_hour = 00, 12, 12,

end_minute = 00, 00, 00,

end_second = 00, 00, 00,

interval_seconds = 21600

input_from_file = .true.,.true.,.true.,

history_interval = 180, 60, 60,

frames_per_outfile = 1000, 1000, 1000,

restart = .false.,

restart_interval = 5000,

io_form_history = 2

io_form_restart = 2

io_form_input = 2

io_form_boundary = 2

debug_level = 0

&domains

time_step = 90,

time_step_fract_num = 0,

time_step_fract_den = 1,

max_dom = 1,

e_we = 150, 112, 94,

e_sn = 140, 97, 91,

e_vert = 51, 30, 30,

p_top_requested = 5000,

num_metgrid_levels = 32,

num_metgrid_soil_levels = 4,

dx = 18000, 10000, 3333.33,

dy = 18000, 10000, 3333.33,

grid_id = 1, 2, 3,

parent_id = 0, 1, 2,

i_parent_start = 1, 31, 30,

j_parent_start = 1, 17, 30,

parent_grid_ratio = 1, 3, 3,

parent_time_step_ratio = 1, 3, 3,

feedback = 1,

eta_levels = 1.0, 0.994, 0.986, 0.978, 0.968, 0.957, 0.945,

0.931, 0.915, 0.897, 0.876, 0.854, 0.829, 0.802,

0.772, 0.740, 0.705, 0.668, 0.629, 0.588, 0.550,

0.513, 0.478, 0.445, 0.413, 0.383, 0.355, 0.328,

0.303, 0.279, 0.256, 0.234, 0.214, 0.195, 0.177,

0.160, 0.144, 0.128, 0.114, 0.101, 0.088, 0.076,

0.065, 0.055, 0.045, 0.036, 0.028, 0.020, 0.012,

0.0056, 0.0

smooth_option = 0

&physics

physics_suite = 'Tropical'

mp_physics = 6, 10, 10, 10,

ra_lw_physics = 1, 1, 1, 1,

ra_sw_physics = 1, 1, 1, 1,

radt = 30, 30, 30, 30,

sf_sfclay_physics = 1, 1, 1, 1,

sf_surface_physics= 4, 4, 4, 4,

bl_pbl_physics = 1, 8, 8, 8,

bldt = 0, 0, 0, 0,

cu_physics = 1, 0, 0, 0,

num_land_cat = 24,

num_soil_layers = 4,

lightning_option = 2, 3, 3, 3,

iccg_method= 1,

iccg_prescribed_num = 0,

iccg_prescribed_den = 1,

do_radar_ref = 1,

cellcount_method = 1,

lightning_start_seconds = 600,

flashrate_factor = 1.0,

cldtop_adjustment = 2,

lightning_dt = 90,

&fdda

&dynamics

w_damping = 0,

diff_opt = 1, 1, 1,

km_opt = 4, 4, 4,

diff_6th_opt = 0, 0, 0,

diff_6th_factor = 0.12, 0.12, 0.12,

base_temp = 290.

damp_opt = 0,

zdamp = 5000., 5000., 5000.,

dampcoef = 0.2, 0.2, 0.2

khdif = 0, 0, 0,

kvdif = 0, 0, 0,

non_hydrostatic = .true., .true., .true.,

moist_adv_opt = 1, 1, 1,

scalar_adv_opt = 1, 1, 1,

gwd_opt = 1,

&bdy_control

spec_bdy_width = 5,

spec_zone = 1,

relax_zone = 4,

specified = .true., .false.,.false.,

nested = .false., .true., .true.,

&grib2

&namelist_quilt

nio_tasks_per_group = 0,

nio_groups = 1,

Kindly help me out.
Thank you.

SRINIVAS

Mary Barth

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Jun 21, 2021, 1:10:48 PM6/21/21

to srinivas nekkali, wrf-chem-lightning

Hello Srnivas,

There are a couple of things I noticed.

1) The iccg numerator is set to 0 which means there will be no IC flashes.

lightning_option = 2, 3, 3, 3,

iccg_method= 1,

iccg_prescribed_num = 0,

iccg_prescribed_den = 1,

2) The grid spacing is set to 18 km which will not represent convection explicitly and the lightning option is set for grid spacings of <= 4 or 5 km where convection is better represented. For parameterized convection, use lightning_option = 11. Here's a suggested namelist for your case:

lightning_option = 11, 11,

iccg_method = 1,

iccg_prescribed_num = 3,

iccg_prescribed_den = 1,

lightning_dt                        = 90, 60,
cellcount_method               = 0, 0,
lightning_start_seconds     = 600, 600,
flashrate_factor                  = 1., 1.,
cldtop_adjustment             = 0, 0,

I would read the literature to see if there is information on IC versus CG flashes in tropical storms. I chose 25% of flashes are CG as sort of a standard value. If you have a IC to CG ratio that you would recommend for tropical cyclones, or those that you are studying in the Indian Ocean, I'd be interested to hear that.