stormchasegenie
Member
Greetings,
My name is Stefan, a postdoc at UCLA. I am finding a systematic wet bias in summertime in my 3-km experiment (see Fig A) across southeastern CA. One-way nesting is used. The ndown namelist and the run namelist are attached, and the 3-km experiment is run using BC information from a parent 9-km simulation.
Based on IVT, it seems as though there are "blobs" of moisture seeping into the domain (Fig. D) and increased surface evaporation at the surface (Fig. E). The 9-km forcing experiment is slightly wet- biased across the region. Since I am running with cu_physics off in the 3-km experiments, the vertical velocities resolved should be larger in the summertime, particularly under a monsoon regime, so I anticipate that, to reduce this wet bias, I should probably use w_damping = 1 (currently it is 0) or play around with my spec_bdy_width options (currently default).
What does w_damping do exactly? I know it "flexes" the vertical CFL condition, and when I ran a perturbation experiment with w_damping = 1, the results did not change much.
Does cugdx = 0 only work for GD cu_physics when dx < 5 km? It seems strange that this would be the case since you shouldn't really be using a CuP for such small grid spacings.
I am trying to figure out how to reduce this bias, but since this is a rather CPU intensive job, I thought you could lend some insight.
Thanks in advance
,
-Stefan
NAMELISTS
RUN 3-km
&time_control
run_days = 16,
run_hours = 0,
run_minutes = 0,
run_seconds = 0,
start_year = 2010, 2010, 2010, 2010
start_month = 08, 08, 08,
start_day = 16, 01, 01,
start_hour = 00, 00, 00,
end_year = 2010, 2010, 2010, 2010
end_month = 09, 09, 09,
end_day = 01, 01, 01,
end_hour = 00, 00, 00,
interval_seconds = 21600
input_from_file = .true.,.true.,.true.,
history_interval = 360, 360, 360,
frames_per_outfile = 1, 1, 1,
restart = .true.,
restart_interval = 14400,
write_hist_at_0h_rst = .true.
adjust_output_times = .true.,
override_restart_timers = .true.
io_form_history = 2
io_form_restart = 2
io_form_input = 2
io_form_boundary = 2
io_form_auxinput2 = 2
io_form_auxinput4 = 2
auxinput4_inname = "wrflowinp_d<domain>",
auxinput4_interval_m = 360, 360, 360, 360,
output_diagnostics = 1
auxhist3_outname = "minmax_d<domain>_<date>",
auxhist3_interval = 1440,
frames_per_auxhist3 = 1,
io_form_auxhist3 = 2
auxhist7_outname = "auxhist_d<domain>_<date>",
auxhist7_interval = 60,
frames_per_auxhist7 = 1, 1,
io_form_auxhist7 = 2
debug_level = 0,
/
&domains
time_step = 180,
use_adaptive_time_step = .true.
step_to_output_time = .true.
target_cfl = 1.2
max_step_increase_pct = 5, 51
starting_time_step = 18
max_time_step = 24
min_time_step = 12
time_step_fract_num = 0,
time_step_fract_den = 1,
max_dom = 1,
parent_id = 2, 2,
parent_grid_ratio = 3, 3,
i_parent_start = 45, 168
j_parent_start = 89, 131
s_we = 1, 1,
s_sn = 1, 1,
e_we = 244, 193,
e_sn = 493, 292,
e_vert = 40, 40, 40,
p_top_requested = 5000,
num_metgrid_levels = 26,
num_metgrid_soil_levels = 4,
dx = 3000, 3000,
dy = 3000, 3000,
grid_id = 3, 4,
parent_time_step_ratio = 3, 3,
feedback = 0,
smooth_option = 0
smooth_cg_topo = .true.,
/
&physics
mp_physics = 51, 51, 51,
cu_physics = 0, 0,
ra_lw_physics = 4, 4, 4,
ra_sw_physics = 4, 4, 4,
bl_pbl_physics = 1, 1, 1,
sf_sfclay_physics = 1, 1, 1,
sf_surface_physics = 4, 4, 4,
radt = 3, 3,
bldt = 0, 0, 0,
cudt = 0, 0, 0,
icloud = 1,
num_land_cat = 21,
sf_urban_physics = 0, 0, 0,
sst_update = 1,
sst_skin = 1,
sf_lake_physics = 1, 1, 1,
use_lakedepth = 1, 1, 1,
co2_ppmv = 386.50418
ch4_ppbv = 1845.6553
/
&noah_mp
opt_run = 1,
opt_sfc = 1,
opt_rsf = 1,
opt_snf = 1,
opt_rad = 1
/
&fdda
grid_fdda = 0
gfdda_inname = "wrffdda_d<domain>"
gfdda_interval_m = 360,
gfdda_end_h = 4800000,
io_form_gfdda = 2
fgdt = 0,
if_no_pbl_nudging_uv = 1
if_no_pbl_nudging_t = 1
if_no_pbl_nudging_q = 1
if_no_pbl_nudging_ph = 1
if_zfac_uv = 0
if_zfac_t = 0
if_zfac_q = 0
guv = 0.0003
gt = 0.0003
gq = 0.0
gph = 0.0003
xwavenum = 3
ywavenum = 3
/
&dynamics
hybrid_opt = 0,
w_damping = 0,
diff_opt = 2, 1, 1, 1,
km_opt = 4, 4, 4, 4,
diff_6th_opt = 0, 0, 0, 0,
diff_6th_factor = 0.12, 0.12, 0.12, 0.12,
base_temp = 290.
damp_opt = 3,
zdamp = 10000., 10000., 10000.,
dampcoef = 0.2, 0.2, 0.2, 0.2,
khdif = 0, 0, 0, 0.,
kvdif = 0, 0, 0, 0.,
non_hydrostatic = .true., .true., .true., .true.,
moist_adv_opt = 1, 1, 1, 1,
scalar_adv_opt = 1, 1, 1, 1,
gwd_opt = 0,
/
&bdy_control
spec_bdy_width = 5,
specified = .true.
/
&grib2
/
&namelist_quilt
nio_tasks_per_group = 0,
nio_groups = 1,
/
NDOWN
run_hours = 0,
run_minutes = 0,
run_seconds = 0,
start_year = 2009, 2009, 2009, 2009
start_month = 08, 08, 08,
start_day = 01, 01, 01,
start_hour = 00, 00, 00,
end_year = 2010, 2010, 2010, 2010
end_month = 09, 09, 09,
end_day = 01, 01, 01,
end_hour = 00, 00, 00,
interval_seconds = 21600
input_from_file = .true.,.true.,.true.,
history_interval = 360, 360, 360,
frames_per_outfile = 1, 1, 1,
restart = .false.,
restart_interval = 14400,
write_hist_at_0h_rst = .true.
adjust_output_times = .true.,
override_restart_timers = .true.
io_form_history = 2
io_form_restart = 2
io_form_input = 2
io_form_boundary = 2
io_form_auxinput2 = 2
io_form_auxinput4 = 2
auxinput4_inname = "wrflowinp_d<domain>",
auxinput4_interval_m = 360, 360, 360, 360,
output_diagnostics = 1
auxhist3_outname = "minmax_d<domain>_<date>",
auxhist3_interval = 1440,
frames_per_auxhist3 = 1,
io_form_auxhist3 = 2
auxhist7_outname = "auxhist_d<domain>_<date>",
auxhist7_interval = 60,
frames_per_auxhist7 = 1, 1,
io_form_auxhist7 = 2
debug_level = 0,
/
&domains
time_step = 120,
use_adaptive_time_step = .ture.
step_to_output_time = .true.
target_cfl = 1.2
max_step_increase_pct = 5, 51
starting_time_step = 180
max_time_step = 360
min_time_step = 120
time_step_fract_num = 0,
time_step_fract_den = 1,
max_dom = 2,
parent_id = 1, 2, 2,
parent_grid_ratio = 5, 3, 3,
i_parent_start = 36, 45, 168
j_parent_start = 19, 89, 131
s_we = 1, 1, 1,
s_sn = 1, 1, 1,
e_we = 271, 244, 193,
e_sn = 341, 493, 292,
e_vert = 40, 40, 40,
p_top_requested = 5000,
num_metgrid_levels = 26,
num_metgrid_soil_levels = 4,
dx = 9000, 3000, 3000,
dy = 9000, 3000, 3000,
grid_id = 2, 3, 4,
parent_time_step_ratio = 5, 3, 3,
feedback = 0,
smooth_option = 0
smooth_cg_topo = .true.,
/
&physics
mp_physics = 51, 51, 51,
cu_physics = 6, 0, 0,
ra_lw_physics = 4, 4, 4,
ra_sw_physics = 4, 4, 4,
bl_pbl_physics = 1, 1, 1,
sf_sfclay_physics = 1, 1, 1,
sf_surface_physics = 4, 4, 4,
radt = 9, 3, 3,
bldt = 0, 0, 0,
cudt = 0, 0, 0,
icloud = 1,
num_land_cat = 21,
sf_urban_physics = 0, 0, 0,
sst_update = 1,
sst_skin = 1,
sf_lake_physics = 1, 1, 1,
use_lakedepth = 1, 1, 1,
co2_ppmv = 386.50418
ch4_ppbv = 1845.6553
/
&noah_mp
opt_run = 1,
opt_sfc = 1,
opt_rsf = 1,
opt_snf = 1,
opt_rad = 1
/
&fdda
grid_fdda = 0
gfdda_inname = "wrffdda_d<domain>"
gfdda_interval_m = 360,
gfdda_end_h = 4800000,
io_form_gfdda = 2
fgdt = 0,
if_no_pbl_nudging_uv = 1
if_no_pbl_nudging_t = 1
if_no_pbl_nudging_q = 1
if_no_pbl_nudging_ph = 1
if_zfac_uv = 0
if_zfac_t = 0
if_zfac_q = 0
guv = 0.0003
gt = 0.0003
gq = 0.0
gph = 0.0003
xwavenum = 3
ywavenum = 3
/
&dynamics
hybrid_opt = 0,
w_damping = 0,
diff_opt = 2, 1, 1, 1,
km_opt = 4, 4, 4, 4,
diff_6th_opt = 0, 0, 0, 0,
diff_6th_factor = 0.12, 0.12, 0.12, 0.12,
base_temp = 290.
damp_opt = 3,
zdamp = 10000., 10000., 10000.,
dampcoef = 0.2, 0.2, 0.2, 0.2,
khdif = 0, 0, 0, 0.,
kvdif = 0, 0, 0, 0.,
non_hydrostatic = .true., .true., .true., .true.,
moist_adv_opt = 1, 1, 1, 1,
scalar_adv_opt = 1, 1, 1, 1,
gwd_opt = 0,
/
&bdy_control
spec_bdy_width = 5,
specified = .true.
/
&grib2
/
&namelist_quilt
nio_tasks_per_group = 0,
nio_groups = 1,
/
My name is Stefan, a postdoc at UCLA. I am finding a systematic wet bias in summertime in my 3-km experiment (see Fig A) across southeastern CA. One-way nesting is used. The ndown namelist and the run namelist are attached, and the 3-km experiment is run using BC information from a parent 9-km simulation.
Based on IVT, it seems as though there are "blobs" of moisture seeping into the domain (Fig. D) and increased surface evaporation at the surface (Fig. E). The 9-km forcing experiment is slightly wet- biased across the region. Since I am running with cu_physics off in the 3-km experiments, the vertical velocities resolved should be larger in the summertime, particularly under a monsoon regime, so I anticipate that, to reduce this wet bias, I should probably use w_damping = 1 (currently it is 0) or play around with my spec_bdy_width options (currently default).
What does w_damping do exactly? I know it "flexes" the vertical CFL condition, and when I ran a perturbation experiment with w_damping = 1, the results did not change much.
Does cugdx = 0 only work for GD cu_physics when dx < 5 km? It seems strange that this would be the case since you shouldn't really be using a CuP for such small grid spacings.
I am trying to figure out how to reduce this bias, but since this is a rather CPU intensive job, I thought you could lend some insight.
Thanks in advance
-Stefan
NAMELISTS
RUN 3-km
&time_control
run_days = 16,
run_hours = 0,
run_minutes = 0,
run_seconds = 0,
start_year = 2010, 2010, 2010, 2010
start_month = 08, 08, 08,
start_day = 16, 01, 01,
start_hour = 00, 00, 00,
end_year = 2010, 2010, 2010, 2010
end_month = 09, 09, 09,
end_day = 01, 01, 01,
end_hour = 00, 00, 00,
interval_seconds = 21600
input_from_file = .true.,.true.,.true.,
history_interval = 360, 360, 360,
frames_per_outfile = 1, 1, 1,
restart = .true.,
restart_interval = 14400,
write_hist_at_0h_rst = .true.
adjust_output_times = .true.,
override_restart_timers = .true.
io_form_history = 2
io_form_restart = 2
io_form_input = 2
io_form_boundary = 2
io_form_auxinput2 = 2
io_form_auxinput4 = 2
auxinput4_inname = "wrflowinp_d<domain>",
auxinput4_interval_m = 360, 360, 360, 360,
output_diagnostics = 1
auxhist3_outname = "minmax_d<domain>_<date>",
auxhist3_interval = 1440,
frames_per_auxhist3 = 1,
io_form_auxhist3 = 2
auxhist7_outname = "auxhist_d<domain>_<date>",
auxhist7_interval = 60,
frames_per_auxhist7 = 1, 1,
io_form_auxhist7 = 2
debug_level = 0,
/
&domains
time_step = 180,
use_adaptive_time_step = .true.
step_to_output_time = .true.
target_cfl = 1.2
max_step_increase_pct = 5, 51
starting_time_step = 18
max_time_step = 24
min_time_step = 12
time_step_fract_num = 0,
time_step_fract_den = 1,
max_dom = 1,
parent_id = 2, 2,
parent_grid_ratio = 3, 3,
i_parent_start = 45, 168
j_parent_start = 89, 131
s_we = 1, 1,
s_sn = 1, 1,
e_we = 244, 193,
e_sn = 493, 292,
e_vert = 40, 40, 40,
p_top_requested = 5000,
num_metgrid_levels = 26,
num_metgrid_soil_levels = 4,
dx = 3000, 3000,
dy = 3000, 3000,
grid_id = 3, 4,
parent_time_step_ratio = 3, 3,
feedback = 0,
smooth_option = 0
smooth_cg_topo = .true.,
/
&physics
mp_physics = 51, 51, 51,
cu_physics = 0, 0,
ra_lw_physics = 4, 4, 4,
ra_sw_physics = 4, 4, 4,
bl_pbl_physics = 1, 1, 1,
sf_sfclay_physics = 1, 1, 1,
sf_surface_physics = 4, 4, 4,
radt = 3, 3,
bldt = 0, 0, 0,
cudt = 0, 0, 0,
icloud = 1,
num_land_cat = 21,
sf_urban_physics = 0, 0, 0,
sst_update = 1,
sst_skin = 1,
sf_lake_physics = 1, 1, 1,
use_lakedepth = 1, 1, 1,
co2_ppmv = 386.50418
ch4_ppbv = 1845.6553
/
&noah_mp
opt_run = 1,
opt_sfc = 1,
opt_rsf = 1,
opt_snf = 1,
opt_rad = 1
/
&fdda
grid_fdda = 0
gfdda_inname = "wrffdda_d<domain>"
gfdda_interval_m = 360,
gfdda_end_h = 4800000,
io_form_gfdda = 2
fgdt = 0,
if_no_pbl_nudging_uv = 1
if_no_pbl_nudging_t = 1
if_no_pbl_nudging_q = 1
if_no_pbl_nudging_ph = 1
if_zfac_uv = 0
if_zfac_t = 0
if_zfac_q = 0
guv = 0.0003
gt = 0.0003
gq = 0.0
gph = 0.0003
xwavenum = 3
ywavenum = 3
/
&dynamics
hybrid_opt = 0,
w_damping = 0,
diff_opt = 2, 1, 1, 1,
km_opt = 4, 4, 4, 4,
diff_6th_opt = 0, 0, 0, 0,
diff_6th_factor = 0.12, 0.12, 0.12, 0.12,
base_temp = 290.
damp_opt = 3,
zdamp = 10000., 10000., 10000.,
dampcoef = 0.2, 0.2, 0.2, 0.2,
khdif = 0, 0, 0, 0.,
kvdif = 0, 0, 0, 0.,
non_hydrostatic = .true., .true., .true., .true.,
moist_adv_opt = 1, 1, 1, 1,
scalar_adv_opt = 1, 1, 1, 1,
gwd_opt = 0,
/
&bdy_control
spec_bdy_width = 5,
specified = .true.
/
&grib2
/
&namelist_quilt
nio_tasks_per_group = 0,
nio_groups = 1,
/
NDOWN
run_hours = 0,
run_minutes = 0,
run_seconds = 0,
start_year = 2009, 2009, 2009, 2009
start_month = 08, 08, 08,
start_day = 01, 01, 01,
start_hour = 00, 00, 00,
end_year = 2010, 2010, 2010, 2010
end_month = 09, 09, 09,
end_day = 01, 01, 01,
end_hour = 00, 00, 00,
interval_seconds = 21600
input_from_file = .true.,.true.,.true.,
history_interval = 360, 360, 360,
frames_per_outfile = 1, 1, 1,
restart = .false.,
restart_interval = 14400,
write_hist_at_0h_rst = .true.
adjust_output_times = .true.,
override_restart_timers = .true.
io_form_history = 2
io_form_restart = 2
io_form_input = 2
io_form_boundary = 2
io_form_auxinput2 = 2
io_form_auxinput4 = 2
auxinput4_inname = "wrflowinp_d<domain>",
auxinput4_interval_m = 360, 360, 360, 360,
output_diagnostics = 1
auxhist3_outname = "minmax_d<domain>_<date>",
auxhist3_interval = 1440,
frames_per_auxhist3 = 1,
io_form_auxhist3 = 2
auxhist7_outname = "auxhist_d<domain>_<date>",
auxhist7_interval = 60,
frames_per_auxhist7 = 1, 1,
io_form_auxhist7 = 2
debug_level = 0,
/
&domains
time_step = 120,
use_adaptive_time_step = .ture.
step_to_output_time = .true.
target_cfl = 1.2
max_step_increase_pct = 5, 51
starting_time_step = 180
max_time_step = 360
min_time_step = 120
time_step_fract_num = 0,
time_step_fract_den = 1,
max_dom = 2,
parent_id = 1, 2, 2,
parent_grid_ratio = 5, 3, 3,
i_parent_start = 36, 45, 168
j_parent_start = 19, 89, 131
s_we = 1, 1, 1,
s_sn = 1, 1, 1,
e_we = 271, 244, 193,
e_sn = 341, 493, 292,
e_vert = 40, 40, 40,
p_top_requested = 5000,
num_metgrid_levels = 26,
num_metgrid_soil_levels = 4,
dx = 9000, 3000, 3000,
dy = 9000, 3000, 3000,
grid_id = 2, 3, 4,
parent_time_step_ratio = 5, 3, 3,
feedback = 0,
smooth_option = 0
smooth_cg_topo = .true.,
/
&physics
mp_physics = 51, 51, 51,
cu_physics = 6, 0, 0,
ra_lw_physics = 4, 4, 4,
ra_sw_physics = 4, 4, 4,
bl_pbl_physics = 1, 1, 1,
sf_sfclay_physics = 1, 1, 1,
sf_surface_physics = 4, 4, 4,
radt = 9, 3, 3,
bldt = 0, 0, 0,
cudt = 0, 0, 0,
icloud = 1,
num_land_cat = 21,
sf_urban_physics = 0, 0, 0,
sst_update = 1,
sst_skin = 1,
sf_lake_physics = 1, 1, 1,
use_lakedepth = 1, 1, 1,
co2_ppmv = 386.50418
ch4_ppbv = 1845.6553
/
&noah_mp
opt_run = 1,
opt_sfc = 1,
opt_rsf = 1,
opt_snf = 1,
opt_rad = 1
/
&fdda
grid_fdda = 0
gfdda_inname = "wrffdda_d<domain>"
gfdda_interval_m = 360,
gfdda_end_h = 4800000,
io_form_gfdda = 2
fgdt = 0,
if_no_pbl_nudging_uv = 1
if_no_pbl_nudging_t = 1
if_no_pbl_nudging_q = 1
if_no_pbl_nudging_ph = 1
if_zfac_uv = 0
if_zfac_t = 0
if_zfac_q = 0
guv = 0.0003
gt = 0.0003
gq = 0.0
gph = 0.0003
xwavenum = 3
ywavenum = 3
/
&dynamics
hybrid_opt = 0,
w_damping = 0,
diff_opt = 2, 1, 1, 1,
km_opt = 4, 4, 4, 4,
diff_6th_opt = 0, 0, 0, 0,
diff_6th_factor = 0.12, 0.12, 0.12, 0.12,
base_temp = 290.
damp_opt = 3,
zdamp = 10000., 10000., 10000.,
dampcoef = 0.2, 0.2, 0.2, 0.2,
khdif = 0, 0, 0, 0.,
kvdif = 0, 0, 0, 0.,
non_hydrostatic = .true., .true., .true., .true.,
moist_adv_opt = 1, 1, 1, 1,
scalar_adv_opt = 1, 1, 1, 1,
gwd_opt = 0,
/
&bdy_control
spec_bdy_width = 5,
specified = .true.
/
&grib2
/
&namelist_quilt
nio_tasks_per_group = 0,
nio_groups = 1,
/