GFS saSAS Shallow Convection Module

This subroutine contains the entirety of the SAMF shallow convection scheme.This routine follows the GFS saSAS Deep Convection 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. More...

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, evef, pgcon, asolfac, hwrf_samfshal, errmsg, errflg)

Detailed Description

Argument Table

local_name	standard_name	long_name	units	type	dimensions	kind	intent
im	horizontal_loop_extent	horizontal loop extent	count	integer	()		in
km	vertical_layer_dimension	vertical layer dimension	count	integer	()		in
itc	index_of_first_chemical_tracer_for_convection	index of first chemical tracer transported/scavenged by convection	index	integer	()		in
ntc	number_of_chemical_tracers	number of chemical tracers	count	integer	()		in
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
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
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
eps	ratio_of_dry_air_to_water_vapor_gas_constants	rd/rv	none	real	()	kind_phys	in
epsm1	ratio_of_dry_air_to_water_vapor_gas_constants_minus_one	(rd/rv) - 1	none	real	()	kind_phys	in
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
grav	gravitational_acceleration	gravitational acceleration	m s-2	real	()	kind_phys	in
hvap	latent_heat_of_vaporization_of_water_at_0c	latent heat of evaporation/sublimation	J kg-1	real	()	kind_phys	in
rd	gas_constant_of_dry_air	ideal gas constant for dry air	J kg-1 K-1	real	()	kind_phys	in
rv	gas_constant_water_vapor	ideal gas constant for water vapor	J kg-1 K-1	real	()	kind_phys	in
t0c	temperature_at_zero_celsius	temperature at 0 degree Celsius	K	real	()	kind_phys	in
delt	timestep_for_physics	physics time step	s	real	()	kind_phys	in
ntk	index_for_turbulent_kinetic_energy_convective_transport_tracer	index for turbulent kinetic energy in the convectively transported tracer array	index	integer	()		in
ntr	number_of_tracers_for_samf	number of tracers for scale-aware mass flux schemes	count	integer	()		in
delp	air_pressure_difference_between_midlayers	pres(k) - pres(k+1)	Pa	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	in
prslp	air_pressure	mean layer pressure	Pa	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	in
psp	surface_air_pressure	surface pressure	Pa	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
phil	geopotential	layer geopotential	m2 s-2	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	in
qtr	convective_transportable_tracers	array to contain cloud water and other convective trans. tracers	kg kg-1	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension, ccpp_constant_one:number_of_tracers_for_convective_transport)	kind_phys	inout
q1	specific_humidity_of_new_state	updated vapor specific humidity	kg kg-1	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	inout
t1	air_temperature_of_new_state	updated temperature	K	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	inout
u1	x_wind_of_new_state	updated x-direction wind	m s-1	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	inout
v1	y_wind_of_new_state	updated y-direction wind	m s-1	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	inout
fscav	chemical_tracer_scavenging_fractions	array of aerosol scavenging coefficients	none	real	(ccpp_constant_one:number_of_chemical_tracers)	kind_phys	in
rn	lwe_thickness_of_shallow_convective_precipitation_amount	shallow convective rainfall amount on physics timestep	m	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	out
kbot	vertical_index_at_cloud_base	index at cloud base	index	integer	(ccpp_constant_one:horizontal_loop_extent)		out
ktop	vertical_index_at_cloud_top	index at cloud top	index	integer	(ccpp_constant_one:horizontal_loop_extent)		out
kcnv	flag_deep_convection	deep convection: 0=no, 1=yes	flag	integer	(ccpp_constant_one:horizontal_loop_extent)		inout
islimsk	sea_land_ice_mask	landmask: sea/land/ice=0/1/2	flag	integer	(ccpp_constant_one:horizontal_loop_extent)		in
garea	cell_area	grid cell area	m2	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
dot	lagrangian_tendency_of_air_pressure	layer mean vertical velocity	Pa s-1	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	in
ncloud	number_of_condensate_species	number of cloud condensate types	count	integer	()		in
hpbl	atmosphere_boundary_layer_thickness	PBL top height	m	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
ud_mf	instantaneous_atmosphere_updraft_convective_mass_flux	(updraft mass flux) * delt	kg m-2	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	out
dt_mf	instantaneous_atmosphere_detrainment_convective_mass_flux	(detrainment mass flux) * delt	kg m-2	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	out
cnvw	convective_cloud_water_mixing_ratio	moist convective cloud water mixing ratio	kg kg-1	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	out
cnvc	convective_cloud_cover	convective cloud cover	frac	real	(ccpp_constant_one:horizontal_loop_extent, ccpp_constant_one:vertical_layer_dimension)	kind_phys	out
clam	entrainment_rate_coefficient_for_shallow_convection	entrainment rate coefficient for shal conv.	none	real	()	kind_phys	in
c0s	rain_conversion_parameter_for_shallow_convection	convective rain conversion parameter for shal conv.	m-1	real	()	kind_phys	in
c1	detrainment_conversion_parameter_for_shallow_convection	convective detrainment conversion parameter for shal conv.	m-1	real	()	kind_phys	in
evef	rain_evaporation_coefficient_for_convection	convective rain evaporation coefficient for convection	frac	real	()	kind_phys	in
pgcon	momentum_transport_reduction_factor_due_to_pressure_gradient_force_for_shallow_convection	reduction factor in momentum transport due to shal conv. induced pressure gradient force	frac	real	()	kind_phys	in
asolfac	aerosol_aware_multiplicative_rain_conversion_parameter_for_shallow_convection	aerosol-aware parameter inversely proportional to CCN number concentraion from Lim (2011) for shal conv.	none	real	()	kind_phys	in
hwrf_samfshal	flag_for_hurricane_specific_code_in_scale_aware_mass_flux_shallow_convection	flag for hwrf samfshalcnv scheme	flag	logical	()		in
errmsg	ccpp_error_message	error message for error handling in CCPP	none	character	()	len=*	out
errflg	ccpp_error_code	error code for error handling in CCPP	1	integer	()		out

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