GFS Scale-Aware Mass-Flux Deep Convection Scheme Module

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

Detailed Description

For grid sizes larger than threshold value, as in Grell (1993) [71] , the SAMF deep convection scheme can be described in terms of three types of "controls": static, dynamic, and feedback. The static control component consists of the simple entraining/detraining updraft/downdraft cloud model and is used to determine the cloud properties, convective precipitation, as well as the convective cloud top height. The dynamic control is the determination of the potential energy available for convection to "consume", or how primed the large-scale environment is for convection to occur due to changes by the dyanmics of the host model. The feedback control is the determination of how the parameterized convection changes the large-scale environment (the host model state variables) given the changes to the state variables per unit cloud base mass flux calculated in the static control portion and the deduced cloud base mass flux determined from the dynamic control.

For grid sizes smaller than threshold value, the cloud base mass flux in the SAMF scheme is determined by the cumulus updraft velocity averaged ove the whole cloud depth (Han et al. (2017) [77] ), which in turn, determines changes of the large-scale environment due to the cumulus convection.

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
ix	horizontal_dimension	horizontal dimension	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 degrees 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
do_ca	flag_for_cellular_automata	cellular automata main switch	flag	logical	()		in	False
ca_deep	fraction_of_cellular_automata_for_deep_convection	fraction of cellular automata for deep convection	frac	real	(horizontal_dimension)	kind_phys	in	False
cldwrk	cloud_work_function	cloud work function	m2 s-2	real	(horizontal_dimension)	kind_phys	out	False
rn	lwe_thickness_of_deep_convective_precipitation_amount	deep convective rainfall amount on physics timestep	m	real	(horizontal_dimension)	kind_phys	out	False
kbot	vertical_index_at_cloud_base	index for cloud base	index	integer	(horizontal_dimension)		out	False
ktop	vertical_index_at_cloud_top	index for 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
ud_mf	instantaneous_atmosphere_updraft_convective_mass_flux	(updraft mass flux) * delt	kg m-2	real	(horizontal_dimension, vertical_dimension)	kind_phys	out	False
dd_mf	instantaneous_atmosphere_downdraft_convective_mass_flux	(downdraft 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	inout	False
cnvc	convective_cloud_cover	convective cloud cover	frac	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
qlcn	mass_fraction_of_convective_cloud_liquid_water	mass fraction of convective cloud liquid water	kg kg-1	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
qicn	mass_fraction_of_convective_cloud_ice	mass fraction of convective cloud ice water	kg kg-1	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
w_upi	vertical_velocity_for_updraft	vertical velocity for updraft	m s-1	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
cf_upi	convective_cloud_fraction_for_microphysics	convective cloud fraction for microphysics	frac	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
cnv_mfd	detrained_mass_flux	detrained mass flux	kg m-2 s-1	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
cnv_dqldt	tendency_of_cloud_water_due_to_convective_microphysics	tendency of cloud water due to convective microphysics	kg m-2 s-1	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
clcn	convective_cloud_volume_fraction	convective cloud volume fraction	frac	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
cnv_fice	ice_fraction_in_convective_tower	ice fraction in convective tower	frac	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
cnv_ndrop	number_concentration_of_cloud_liquid_water_particles_for_detrainment	droplet number concentration in convective detrainment	m-3	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
cnv_nice	number_concentration_of_ice_crystals_for_detrainment	crystal number concentration in convective detrainment	m-3	real	(horizontal_dimension, vertical_dimension)	kind_phys	inout	False
mp_phys	flag_for_microphysics_scheme	choice of microphysics scheme	flag	integer	()		in	False
mp_phys_mg	flag_for_morrison_gettelman_microphysics_scheme	choice of Morrison-Gettelman microphysics scheme	flag	integer	()		in	False
clam	entrainment_rate_coefficient_deep_convection	entrainment rate coefficient for deep conv.	none	real	()	kind_phys	in	False
c0s	rain_conversion_parameter_deep_convection	convective rain conversion parameter for deep conv.	m-1	real	()	kind_phys	in	False
c1	detrainment_conversion_parameter_deep_convection	convective detrainment conversion parameter for deep conv.	m-1	real	()	kind_phys	in	False
betal	downdraft_fraction_reaching_surface_over_land_deep_convection	downdraft fraction reaching surface over land for deep conv.	frac	real	()	kind_phys	in	False
betas	downdraft_fraction_reaching_surface_over_ocean_deep_convection	downdraft fraction reaching surface over ocean for deep conv.	frac	real	()	kind_phys	in	False
evfact	rain_evaporation_coefficient_deep_convection	convective rain evaporation coefficient for deep conv.	frac	real	()	kind_phys	in	False
evfactl	rain_evaporation_coefficient_over_land_deep_convection	convective rain evaporation coefficient over land for deep conv.	frac	real	()	kind_phys	in	False
pgcon	momentum_transport_reduction_factor_pgf_deep_convection	reduction factor in momentum transport due to deep conv. induced pressure gradient force	frac	real	()	kind_phys	in	False
asolfac	aerosol_aware_parameter_deep_convection	aerosol-aware parameter inversely proportional to CCN number concentraion from Lim (2011) for deep conv.	none	real	()	kind_phys	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 samfdeepcnv General Algorithm

1. Compute preliminary quantities needed for static, dynamic, and feedback control portions of the algorithm.
2. Perform calculations related to the updraft of the entraining/detraining cloud model ("static control").
3. Perform calculations related to the downdraft of the entraining/detraining cloud model ("static control").
4. For grid sizes larger than the threshold value (currently 8 km):
   • 1) Using the updated temperature and moisture profiles that were modified by the convection on a short time-scale, recalculate the total cloud work function to determine the change in the cloud work function due to convection, or the stabilizing effect of the cumulus.
   • 2) For the "dynamic control", using a reference cloud work function, estimate the change in cloud work function due to the large-scale dynamics. Following the quasi-equilibrium assumption, calculate the cloud base mass flux required to keep the large-scale convective destabilization in balance with the stabilization effect of the convection.
5. For grid sizes smaller than the threshold value (currently 8 km):
   • 1) compute the cloud base mass flux using the cumulus updraft velocity averaged ove the whole cloud depth.
6. For scale awareness, the updraft fraction (sigma) is obtained as a function of cloud base entrainment. Then, the final cloud base mass flux is obtained by the original mass flux multiplied by the (1−sigma) 2 .
7. 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 samfdeepcnv Detailed Algorithm

Functions/Subroutines
subroutine	samfdeepcnv::samfdeepcnv_run (im, ix, 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, do_ca, ca_deep, cldwrk, rn, kbot, ktop, kcnv, islimsk, garea, dot, ncloud, ud_mf, dd_mf, dt_mf, cnvw, cnvc, QLCN, QICN, w_upi, cf_upi, CNV_MFD, CNV_DQLDT, CLCN, CNV_FICE, CNV_NDROP, CNV_NICE, mp_phys, mp_phys_mg, clam, c0s, c1, betal, betas, evfact, evfactl, pgcon, asolfac, errmsg, errflg)