% model parameters
% alpha_c 	Charnock constant
% b		smooth flow constant
% choose parameters:

alpha_c = 0.011;
b = 0.11;

% permanent constants
% nu is air kinematic viscosity
%g = 9.81;
%nu = 1.5e-5;

rho_a = 1.22;

% initialize
u10 = [1:20]';
tau = NaN*ones(length(u10),1);

% Charnock type models:
for n=1:length(u10)
   [ustar,flag] = charnock(u10(n),alpha_c,b);
   if flag == 0
      tau(n) = rho_a * ustar^2;
   end
end

% Large and Pond:
for n=1:length(u10)
      tau(n) = rho_a * (0.0027* u10(n) + 0.000142 * u10(n)^2 + 0.0000764 * u10(n)^3);
end