% AS_CONSTS: returns values of many constants used in AIR_SEA TOOLBOX
% AS_CONSTS: returns values of many constants used in the AIR_SEA
% TOOLBOX. At end of this file are values of constants from COARE
% to be used when running the test program t_hfbulktc.m
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% 8/19/98: version 1.1 (contributed by RP)
% 4/7/99: version 1.2 (revised to include COARE test values by AA)
% 8/5/99: version 2.0
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% ------- physical constants
g = 9.8; % acceleration due to gravity [m/s^2]
sigmaSB = 5.6697e-8; % Stefan-Boltzmann constant [W/m^2/K^4]
eps_air = 0.62197; % molecular weight ratio (water/air)
gas_const_R = 287.04; % gas constant for dry air [J/kg/K]
CtoK = 273.16; % conversion factor for [C] to [K]
% ------- meteorological constants
kappa = 0.4; % von Karman's constant
Charnock_alpha = 0.011; % Charnock constant (for determining roughness length
% at sea given friction velocity), used in Smith
% formulas for drag coefficient and also in Fairall
% and Edson. use alpha=0.011 for open-ocean and
% alpha=0.018 for fetch-limited (coastal) regions.
R_roughness = 0.11; % limiting roughness Reynolds # for aerodynamically
% smooth flow
% ------ defaults suitable for boundary-layer studies
cp = 1004.7; % heat capacity of air [J/kg/K]
rho_air = 1.22; % air density (when required as constant) [kg/m^2]
Ta_default = 10; % default air temperature [C]
P_default = 1020; % default air pressure for Kinneret [mbars]
psych_default = 'screen'; % default psychmometer type (see relhumid.m)
Qsat_coeff = 0.98; % satur. specific humidity coefficient reduced
% by 2% over salt water
% the following are useful in hfbulktc.m
% (and are the default values used in Fairall et al, 1996)
CVB_depth = 600; % depth of convective boundary layer in atmosphere [m]
min_gustiness = 0.5; % min. "gustiness" (i.e., unresolved fluctuations) [m/s]
% should keep this strictly >0, otherwise bad stuff
% might happen (divide by zero errors)
beta_conv = 1.25;% scaling constant for gustiness
% ------ short-wave flux calculations
Solar_const = 1368.0; % the solar constant [W/m^2] represents a
% mean of satellite measurements made over the
% last sunspot cycle (1979-1995) taken from
% Coffey et al (1995), Earth System Monitor, 6, 6-10.
% ------ long-wave flux calculations
emiss_lw = 0.985; % long-wave emissivity of ocean from Dickey et al
% (1994), J. Atmos. Oceanic Tech., 11, 1057-1076.
bulkf_default = 'berliand'; % default bulk formula when downward long-wave
% measurements are not made.
% ------ constants used for COARE; to use simply delete the %
% g = 9.7803; % acceleration due to gravity [m/s^2]
% sigmaSB = 5.67e-8; % Stefan-Boltzmann constant [m^2/K^4]
% gas_const_R = 287.1; % gas constant for dry air [J/kg/K]
% cp = 1004.67; % heat capacity of air [J/kg/K]
% beta_conv = 1.20; % scaling constant for gustiness
% emiss_lw = 0.97; % long-wave emissivity