Scheduled Downtime
On Friday 21 April 2023 @ 5pm MT, this website will be down for maintenance and expected to return online the morning of 24 April 2023 at the latest

Does the shortwave radiation Dudhia scheme (ra_sw_physics=1) have shortwave radiation feedback (direct effect)?

zelunyin

New member
Hi, does the shortwave radiation Dudhia scheme (ra_sw_physics=1) have shortwave radiation feedback (direct effect)? WRF chem users_guide_v4.3 states that direct effect should be used with RRTMG and Goddard scheme. The original article is as follows:(Page 25)

4.3.2 Running with direct effect Shortwave radiative feedbacks or what is known as the direct effect is included with the running of chemistry. To turn on the radiative feedbacks in your simulation you should select either the RRTMG radiation schemes, or the Goddard shortwave scheme and turn on aer_ra_feedback (aer_ra_feedback=1). With these options selected the aerosol shading will be active and one can select an aerosol compostition assumption for the Mie radiation calculation using aer_op_opt. Another namelist option related to radiation that is typically used in a simulation is cu_rad_feedback. When turned on (cu_rad_feedback = .true.) the shortwave and photolysis schemes will include the effects of unresolved clouds in the simulation. Otherwise, the simulation could have a grid cell containing a strong precipitating thunderstorm (parameterized instead of resolved precipitation) but the surface incident radiation and photolysis calculations will produce a result for an environment is totally cloud free. If using the MYNN PBL and TUV schemes, one can also include the impact parameterized boundary layer clouds on photolysis (phot_blcld = .true.)

However, I feel that the Dudhia scheme is better than the RRTMG and Goddard schemes in my simulations, especially for the full layer 550 nm optical thickness. So I would like to ask if the Dudhia scheme also includes (supports) shortwave radiation feedback?

Here is my part of namelist.input.
Thanks

&physics
num_land_cat = 21,
mp_physics = 2,
progn = 0,
ra_lw_physics = 4,
ra_sw_physics = 1,
radt = 27,
sf_sfclay_physics = 1,
sf_surface_physics = 2,
bl_pbl_physics = 1,
bldt = 0,
cu_physics = 3,
cu_diag = 1,
cudt = 0,
ishallow = 0,
isfflx = 1,
ifsnow = 0,
icloud = 1,
surface_input_source = 1,
num_soil_layers = 4,
sf_urban_physics = 0,
mp_zero_out = 2,
mp_zero_out_thresh = 1.e-12,
maxiens = 1,
maxens = 3,
maxens2 = 3,
maxens3 = 16,
ensdim = 144,
cu_rad_feedback = .true.,
/


&fdda
/

&dynamics
rk_ord = 3,
w_damping = 1,
diff_opt = 1,
km_opt = 4,
diff_6th_opt = 0,
diff_6th_factor = 0.12,
base_temp = 290.
damp_opt = 0,
zdamp = 5000.,
dampcoef = 0.01,
khdif = 0,
kvdif = 0,
non_hydrostatic = .true.,
moist_adv_opt = 2,
scalar_adv_opt = 2,
chem_adv_opt = 2,
tke_adv_opt = 2,
time_step_sound = 4,
h_mom_adv_order = 5,
v_mom_adv_order = 3,
h_sca_adv_order = 5,
v_sca_adv_order = 3,
/

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




&chem
kemit = 1,
chem_opt = 301,
bioemdt = 0,
photdt = 30,
chemdt = 10,
io_style_emissions = 0,
emiss_opt = 0,
emiss_opt_vol = 0,
emiss_ash_hgt = 20000.,
chem_in_opt = 0,
phot_opt = 2,
gas_drydep_opt = 1,
aer_drydep_opt = 1,
bio_emiss_opt = 0,
ne_area = 0,
dust_opt = 1,
dmsemis_opt = 0,
seas_opt = 0,
depo_fact = 0.25,
gas_bc_opt = 1,
gas_ic_opt = 1,
aer_bc_opt = 1,
aer_ic_opt = 1,
gaschem_onoff = 1,
aerchem_onoff = 1,
wetscav_onoff = 0,
cldchem_onoff = 0,
vertmix_onoff = 1,
chem_conv_tr = 0,
conv_tr_wetscav = 0,
conv_tr_aqchem = 0,
biomass_burn_opt = 0,
plumerisefire_frq = 30,
have_bcs_chem = .false.,
aer_ra_feedback = 1,
aer_op_opt = 2,
opt_pars_out = 1,
diagnostic_chem = 0,
/
 
If you are referring to direct solar radiation (the variable "swddir" ), then RRTMG, CAM and Goddard radiation schemes can output this variable.

Note that Dudhia radiation scheme doesn't output direct and diffuse radiation separately.
 
Top