function k1 = ozone_k1 ( t )

%*****************************************************************************80
%
%% ozone_k1() evaluates rate coefficient k1 for the ozone ODE.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    05 January 2021
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real T: the current time, in seconds from sunrise.
%
%  Output:
%
%    real K1: the rate coefficient.
%
  td = 24.0 * 60.0 * 60.0;
  k1 = 0.01 * max ( 0.0, sin ( 2.0 * pi * t / td ) );

  return
end

