GFS Surface Layer Module

This module calculates surface roughness length.This subroutine includes the surface roughness length formulation based on the surface sublayer scheme in Zeng and Dickinson (1998) [211]. More...

Functions/Subroutines
subroutine, public	sfc_diff::sfc_diff_run (im, rvrdm1, eps, epsm1, grav, ps, t1, q1, z1, garea, wind, prsl1, prslki, prsik1, prslk1, sigmaf, vegtype, shdmax, ivegsrc, z0pert, ztpert, flag_iter, redrag, flag_lakefreeze, u10m, v10m, sfc_z0_type, u1, v1, usfco, vsfco, icplocn2atm, wet, dry, icy, thsfc_loc, tskin_wat, tskin_lnd, tskin_ice, tsurf_wat, tsurf_lnd, tsurf_ice, z0rl_wat, z0rl_lnd, z0rl_ice, z0rl_wav, ustar_wat, ustar_lnd, ustar_ice, cm_wat, cm_lnd, cm_ice, ch_wat, ch_lnd, ch_ice, rb_wat, rb_lnd, rb_ice, stress_wat, stress_lnd, stress_ice, fm_wat, fm_lnd, fm_ice, fh_wat, fh_lnd, fh_ice, fm10_wat, fm10_lnd, fm10_ice, fh2_wat, fh2_lnd, fh2_ice, ztmax_wat, ztmax_lnd, ztmax_ice, zvfun, errmsg, errflg)
subroutine, public	sfc_diff::stability (z1, zvfun, gdx, tv1, thv1, wind, z0max, ztmax, tvs, grav, thsfc_loc, rb, fm, fh, fm10, fh2, cm, ch, stress, ustar)
subroutine	sfc_diff::znot_m_v6 (uref, znotm)
	add fitted z0,zt curves for hurricane application (used in HWRF/HMON) Weiguo Wang, 2019-0425
subroutine	sfc_diff::znot_t_v6 (uref, znott)
	Calculate scalar roughness over water with input 10-m wind For low-to-moderate winds, try to match the Ck-U10 relationship from COARE algorithm For high winds, try to retain the Ck-U10 relationship of FY2015 HWRF.
subroutine	sfc_diff::znot_m_v7 (uref, znotm)
	Calculate areodynamical roughness over water with input 10-m wind For low-to-moderate winds, try to match the Cd-U10 relationship from COARE V3.5 (Edson et al. 2013) For high winds, try to fit available observational data Comparing to znot_t_v6, slightly decrease Cd for higher wind speed.
subroutine	sfc_diff::znot_t_v7 (uref, znott)
	Calculate scalar roughness over water with input 10-m wind For low-to-moderate winds, try to match the Ck-U10 relationship from COARE algorithm For high winds, try to retain the Ck-U10 relationship of FY2015 HWRF To be compatible with the slightly decreased Cd for higher wind speed.

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
rvrdm1	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
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
grav	gravitational_acceleration	gravitational acceleration	m s-2	real	()	kind_phys	in
ps	surface_air_pressure	surface pressure	Pa	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
t1	air_temperature_at_surface_adjacent_layer	1st model layer air temperature	K	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
q1	specific_humidity_at_surface_adjacent_layer	1st model layer specific humidity	kg kg-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
z1	height_above_ground_at_lowest_model_layer	height above ground at 1st model layer	m	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
garea	cell_area	area of the grid cell	m2	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
zvfun	function_of_surface_roughness_length_and_green_vegetation_fraction	function of surface roughness length and green vegetation fraction	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	out
wind	wind_speed_at_lowest_model_layer	wind speed at lowest model level	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
prsl1	air_pressure_at_surface_adjacent_layer	Model layer 1 mean pressure	Pa	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
prslki	ratio_of_exner_function_between_midlayer_and_interface_at_lowest_model_layer	Exner function ratio bt midlayer and interface at 1st layer	ratio	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
prsik1	surface_dimensionless_exner_function	dimensionless Exner function at the ground surface	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
prslk1	dimensionless_exner_function_at_surface_adjacent_layer	dimensionless Exner function at the lowest model layer	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
sigmaf	bounded_vegetation_area_fraction	areal fractional cover of green vegetation bounded on the bottom	frac	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
vegtype	vegetation_type_classification	vegetation type at each grid cell	index	integer	(ccpp_constant_one:horizontal_loop_extent)		in
shdmax	max_vegetation_area_fraction	max fractnl cover of green veg	frac	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
ivegsrc	control_for_vegetation_dataset	land use dataset choice	index	integer	()		in
z0pert	perturbation_of_momentum_roughness_length	perturbation of momentum roughness length	frac	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
ztpert	perturbation_of_heat_to_momentum_roughness_length_ratio	perturbation of heat to momentum roughness length ratio	frac	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
flag_iter	flag_for_iteration	flag for iteration	flag	logical	(ccpp_constant_one:horizontal_loop_extent)		in
redrag	flag_for_limited_surface_roughness_length_over_ocean	flag for reduced drag coefficient over sea	flag	logical	()		in
flag_lakefreeze	flag_for_lake_water_freeze	flag for lake water freeze	flag	logical	(ccpp_constant_one:horizontal_loop_extent)		in
u10m	x_wind_at_10m	10 meter u wind speed	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
v10m	y_wind_at_10m	10 meter v wind speed	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
u1	x_wind_at_surface_adjacent_layer	x component of surface layer wind	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
v1	y_wind_at_surface_adjacent_layer	y component of surface layer wind	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
usfco	x_ocean_current	zonal current at ocean surface	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
vsfco	y_ocean_current	meridional current at ocean surface	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
sfc_z0_type	flag_for_surface_roughness_option_over_water	surface roughness options over water	flag	integer	()		in
icplocn2atm	control_for_air_sea_flux_computation_over_water	air-sea flux option	1	integer	()		in
wet	flag_nonzero_wet_surface_fraction	flag indicating presence of some ocean or lake surface area fraction	flag	logical	(ccpp_constant_one:horizontal_loop_extent)		inout
dry	flag_nonzero_land_surface_fraction	flag indicating presence of some land surface area fraction	flag	logical	(ccpp_constant_one:horizontal_loop_extent)		in
icy	flag_nonzero_sea_ice_surface_fraction	flag indicating presence of some sea ice surface area fraction	flag	logical	(ccpp_constant_one:horizontal_loop_extent)		in
thsfc_loc	flag_for_reference_pressure_theta	flag for reference pressure in theta calculation	flag	logical	()		in
tskin_wat	surface_skin_temperature_over_water	surface skin temperature over water	K	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
tskin_lnd	surface_skin_temperature_over_land	surface skin temperature over land	K	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
tskin_ice	surface_skin_temperature_over_ice	surface skin temperature over ice	K	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
tsurf_wat	surface_skin_temperature_after_iteration_over_water	surface skin temperature after iteration over water	K	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
tsurf_lnd	surface_skin_temperature_after_iteration_over_land	surface skin temperature after iteration over land	K	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
tsurf_ice	surface_skin_temperature_after_iteration_over_ice	surface skin temperature after iteration over ice	K	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
z0rl_wat	surface_roughness_length_over_water	surface roughness length over water (temporary use as interstitial)	cm	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
z0rl_lnd	surface_roughness_length_over_land	surface roughness length over land (temporary use as interstitial)	cm	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
z0rl_ice	surface_roughness_length_over_ice	surface roughness length over ice (temporary use as interstitial)	cm	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
z0rl_wav	surface_roughness_length_from_wave_model	surface roughness length from wave model	cm	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	in
ustar_wat	surface_friction_velocity_over_water	surface friction velocity over water	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
ustar_lnd	surface_friction_velocity_over_land	surface friction velocity over land	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
ustar_ice	surface_friction_velocity_over_ice	surface friction velocity over ice	m s-1	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
cm_wat	surface_drag_coefficient_for_momentum_in_air_over_water	surface exchange coeff for momentum over water	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
cm_lnd	surface_drag_coefficient_for_momentum_in_air_over_land	surface exchange coeff for momentum over land	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
cm_ice	surface_drag_coefficient_for_momentum_in_air_over_ice	surface exchange coeff for momentum over ice	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
ch_wat	surface_drag_coefficient_for_heat_and_moisture_in_air_over_water	surface exchange coeff heat surface exchange coeff heat & moisture over ocean moisture over water	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
ch_lnd	surface_drag_coefficient_for_heat_and_moisture_in_air_over_land	surface exchange coeff heat & moisture over land	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
ch_ice	surface_drag_coefficient_for_heat_and_moisture_in_air_over_ice	surface exchange coeff heat & moisture over ice	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
rb_wat	bulk_richardson_number_at_lowest_model_level_over_water	bulk Richardson number at the surface over water	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
rb_lnd	bulk_richardson_number_at_lowest_model_level_over_land	bulk Richardson number at the surface over land	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
rb_ice	bulk_richardson_number_at_lowest_model_level_over_ice	bulk Richardson number at the surface over ice	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
stress_wat	surface_wind_stress_over_water	surface wind stress over water	m2 s-2	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
stress_lnd	surface_wind_stress_over_land	surface wind stress over land	m2 s-2	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
stress_ice	surface_wind_stress_over_ice	surface wind stress over ice	m2 s-2	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fm_wat	monin_obukhov_similarity_function_for_momentum_over_water	Monin-Obukhov similarity function for momentum over water	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fm_lnd	monin_obukhov_similarity_function_for_momentum_over_land	Monin-Obukhov similarity function for momentum over land	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fm_ice	monin_obukhov_similarity_function_for_momentum_over_ice	Monin-Obukhov similarity function for momentum over ice	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fh_wat	monin_obukhov_similarity_function_for_heat_over_water	Monin-Obukhov similarity function for heat over water	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fh_lnd	monin_obukhov_similarity_function_for_heat_over_land	Monin-Obukhov similarity function for heat over land	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fh_ice	monin_obukhov_similarity_function_for_heat_over_ice	Monin-Obukhov similarity function for heat over ice	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fm10_wat	monin_obukhov_similarity_function_for_momentum_at_10m_over_water	Monin-Obukhov similarity parameter for momentum at 10m over water	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fm10_lnd	monin_obukhov_similarity_function_for_momentum_at_10m_over_land	Monin-Obukhov similarity parameter for momentum at 10m over land	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fm10_ice	monin_obukhov_similarity_function_for_momentum_at_10m_over_ice	Monin-Obukhov similarity parameter for momentum at 10m over ice	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fh2_wat	monin_obukhov_similarity_function_for_heat_at_2m_over_water	Monin-Obukhov similarity parameter for heat at 2m over water	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fh2_lnd	monin_obukhov_similarity_function_for_heat_at_2m_over_land	Monin-Obukhov similarity parameter for heat at 2m over land	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
fh2_ice	monin_obukhov_similarity_function_for_heat_at_2m_over_ice	Monin-Obukhov similarity parameter for heat at 2m over ice	none	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
ztmax_wat	bounded_surface_roughness_length_for_heat_over_water	bounded surface roughness length for heat over water	m	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
ztmax_lnd	bounded_surface_roughness_length_for_heat_over_land	bounded surface roughness length for heat over land	m	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
ztmax_ice	bounded_surface_roughness_length_for_heat_over_ice	bounded surface roughness length for heat over ice	m	real	(ccpp_constant_one:horizontal_loop_extent)	kind_phys	inout
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 Surface Layer Scheme General Algorithm

• Calculate the thermal roughness length formulation over the ocean (see eq. (25) and (26) in Zeng et al. (1998) [212]).
• Calculate Zeng's momentum roughness length formulation over land and sea ice.
• Calculate the new vegetation-dependent formulation of thermal roughness length (Zheng et al.(2012) [214]). Zheng et al. (2012) [214] proposed a new formulation on \(ln(Z_{0m}^,/Z_{0t})\) as follows:

  \[ ln(Z_{0m}^,/Z_{0t})=(1-GVF)^2C_{zil}k(u*Z_{0g}/\nu)^{0.5} \]

  where \(Z_{0m}^,\) is the effective momentum roughness length computed in the following equation for each grid, \(Z_{0t}\) is the roughness lenghth for heat, \(C_{zil}\) is a coefficient (taken as 0.8), k is the Von Karman constant (0.4), \(\nu=1.5\times10^{-5}m^{2}s^{-1}\) is the molecular viscosity, \(u*\) is the friction velocity, and \(Z_{0g}\) is the bare soil roughness length for momentum (taken as 0.01).
  In order to consider the convergence of \(Z_{0m}\) between fully vegetated and bare soil, the effective \(Z_{0m}^,\) is computed:

  \[ \ln(Z_{0m}^,)=(1-GVF)^{2}\ln(Z_{0g})+\left[1-(1-GVF)^{2}\right]\ln(Z_{0m}) \]

• Calculate the exchange coefficients: \(cm\), \(ch\), and \(stress\) as inputs of other sfc schemes.