function [cd] = dragcoeff_LP81(u);

%
%  [cd] = dragcoeff_LP81(u)
%  
%  given a vector of wind speeds (magnitudes, not velocities, 10 m above
%  ocean surface) returns a vector of corresponding drag coefficients based
%  on the formula [Large and Pond, 1981]:
%
%            { 1.2               ;           |u| <  11 m/s
%  10^3 cd = { 0.49 + 0.065 |u|  ;           |u| >= 11 m/s
%

u_fn = [0:0.01:100]';
i_11 = 11/.01 + 1;

cd_fn = 0.49 + 0.065*u_fn;
cd_fn(1:i_11) = 1.2;

cd = interp1(u_fn, cd_fn, u)*1e-3;
