GFS samfshalcnv Main

This subroutine contains the entirety of the SAMF shallow convection scheme. More...

Detailed Description

This routine follows the GFS samfdeepcnv Main quite closely, although it can be interpreted as only having the "static" and "feedback" control portions, since the "dynamic" control is not necessary to find the cloud base mass flux. The algorithm is simplified from SAMF deep convection by excluding convective downdrafts and being confined to operate below \(p=0.7p_{sfc}\). Also, entrainment is both simpler and stronger in magnitude compared to the deep scheme.

Argument Table

local_name	standard_name	long_name	units	rank	type	kind	intent	optional
im	horizontal_loop_extent	horizontal loop extent	count	0	integer		in	F
ix	horizontal_dimension	horizontal dimension	count	0	integer		in	F
km	vertical_dimension	vertical layer dimension	count	0	integer		in	F
cliq	specific_heat_of_liquid_water_at_constant_pressure	specific heat of liquid water at constant pressure	J kg-1 K-1	0	real	kind_phys	in	F
cp	specific_heat_of_dry_air_at_constant_pressure	specific heat of dry air at constant pressure	J kg-1 K-1	0	real	kind_phys	in	F
cvap	specific_heat_of_water_vapor_at_constant_pressure	specific heat of water vapor at constant pressure	J kg-1 K-1	0	real	kind_phys	in	F
eps	ratio_of_dry_air_to_water_vapor_gas_constants	rd/rv	none	0	real	kind_phys	in	F
epsm1	ratio_of_dry_air_to_water_vapor_gas_constants_minus_one	(rd/rv) - 1	none	0	real	kind_phys	in	F
fv	ratio_of_vapor_to_dry_air_gas_constants_minus_one	(rv/rd) - 1 (rv = ideal gas constant for water vapor)	none	0	real	kind_phys	in	F
grav	gravitational_acceleration	gravitational acceleration	m s-2	0	real	kind_phys	in	F
hvap	latent_heat_of_vaporization_of_water_at_0C	latent heat of evaporation/sublimation	J kg-1	0	real	kind_phys	in	F
rd	gas_constant_dry_air	ideal gas constant for dry air	J kg-1 K-1	0	real	kind_phys	in	F
rv	gas_constant_water_vapor	ideal gas constant for water vapor	J kg-1 K-1	0	real	kind_phys	in	F
t0c	temperature_at_zero_celsius	temperature at 0 degrees Celsius	K	0	real	kind_phys	in	F
delt	time_step_for_physics	physics time step	s	0	real	kind_phys	in	F
ntk	index_of_TKE_convective_transport_tracer	index of TKE in the convectively transported tracer array	index	0	integer		in	F
ntr	number_of_tracers_for_samf	number of tracers for scale-aware mass flux schemes	count	0	integer		in	F
delp	air_pressure_difference_between_midlayers	pres(k) - pres(k+1)	Pa	2	real	kind_phys	in	F
prslp	air_pressure	mean layer pressure	Pa	2	real	kind_phys	in	F
psp	surface_air_pressure	surface pressure	Pa	1	real	kind_phys	in	F
phil	geopotential	layer geopotential	m2 s-2	2	real	kind_phys	in	F
qtr	convective_transportable_tracers	array to contain cloud water and other convective trans. tracers	kg kg-1	3	real	kind_phys	inout	F
q1	water_vapor_specific_humidity_updated_by_physics	updated vapor specific humidity	kg kg-1	2	real	kind_phys	inout	F
t1	air_temperature_updated_by_physics	updated temperature	K	2	real	kind_phys	inout	F
u1	x_wind_updated_by_physics	updated x-direction wind	m s-1	2	real	kind_phys	inout	F
v1	y_wind_updated_by_physics	updated y-direction wind	m s-1	2	real	kind_phys	inout	F
rn	lwe_thickness_of_shallow_convective_precipitation_amount	shallow convective rainfall amount on physics timestep	m	1	real	kind_phys	out	F
kbot	vertical_index_at_cloud_base	index at cloud base	index	1	integer		out	F
ktop	vertical_index_at_cloud_top	index at cloud top	index	1	integer		out	F
kcnv	flag_deep_convection	deep convection: 0=no, 1=yes	flag	1	integer		inout	F
islimsk	sea_land_ice_mask	landmask: sea/land/ice=0/1/2	flag	1	integer		in	F
garea	cell_area	grid cell area	m2	1	real	kind_phys	in	F
dot	omega	layer mean vertical velocity	Pa s-1	2	real	kind_phys	in	F
ncloud	number_of_hydrometeors	number of hydrometeors	count	0	integer		in	F
hpbl	atmosphere_boundary_layer_thickness	PBL top height	m	1	real	kind_phys	in	F
ud_mf	instantaneous_atmosphere_updraft_convective_mass_flux	(updraft mass flux) * delt	kg m-2	2	real	kind_phys	out	F
dt_mf	instantaneous_atmosphere_detrainment_convective_mass_flux	(detrainment mass flux) * delt	kg m-2	2	real	kind_phys	out	F
cnvw	convective_cloud_water_mixing_ratio	moist convective cloud water mixing ratio	kg kg-1	2	real	kind_phys	out	F
cnvc	convective_cloud_cover	convective cloud cover	frac	2	real	kind_phys	out	F
clam	entrainment_rate_coefficient_shallow_convection	entrainment rate coefficient for shal conv.	none	0	real	kind_phys	in	F
c0s	rain_conversion_parameter_shallow_convection	convective rain conversion parameter for shal conv.	m-1	0	real	kind_phys	in	F
c1	detrainment_conversion_parameter_shallow_convection	convective detrainment conversion parameter for shal conv.	m-1	0	real	kind_phys	in	F
pgcon	momentum_transport_reduction_factor_pgf_shallow_convection	reduction factor in momentum transport due to shal conv. induced pressure gradient force	frac	0	real	kind_phys	in	F
asolfac	aerosol_aware_parameter_shallow_convection	aerosol-aware parameter inversely proportional to CCN number concentraion from Lim (2011) for shal conv.	none	0	real	kind_phys	in	F
errmsg	ccpp_error_message	error message for error handling in CCPP	none	0	character	len=*	out	F
errflg	ccpp_error_flag	error flag for error handling in CCPP	flag	0	integer		out	F

GFS samfshalcnv General Algorithm

1. Compute preliminary quantities needed for the static and feedback control portions of the algorithm.
2. Perform calculations related to the updraft of the entraining/detraining cloud model ("static control").
3. The cloud base mass flux is obtained using the cumulus updraft velocity averaged ove the whole cloud depth.
4. Calculate the tendencies of the state variables (per unit cloud base mass flux) and the cloud base mass flux.
5. For the "feedback control", calculate updated values of the state variables by multiplying the cloud base mass flux and the tendencies calculated per unit cloud base mass flux from the static control.

GFS samfshalcnv Detailed Algorithm

Functions/Subroutines
subroutine	samfshalcnv::samfshalcnv_run (im, ix, km, cliq, cp, cvap, eps, epsm1, fv, grav, hvap, rd, rv, t0c, delt, ntk, ntr, delp, prslp, psp, phil, qtr, q1, t1, u1, v1, rn, kbot, ktop, kcnv, islimsk, garea, dot, ncloud, hpbl, ud_mf, dt_mf, cnvw, cnvc, clam, c0s, c1, pgcon, asolfac, errmsg, errflg)