GFS Scale-Aware Mass-Flux Shallow Convection Scheme Module

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

Detailed Description

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

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, km, itc, ntc, cliq, cp, cvap, eps, epsm1, fv, grav, hvap, rd, rv, t0c, delt, ntk, ntr, delp, prslp, psp, phil, qtr, q1, t1, u1, v1, fscav, rn, kbot, ktop, kcnv, islimsk, garea, dot, ncloud, hpbl, ud_mf, dt_mf, cnvw, cnvc, clam, c0s, c1, pgcon, asolfac, hwrf_samfshal, errmsg, errflg)