function Cp = cp_eq9(T,S)
%==========================================================
% Equation (9)
% Calculates Specific Heat of Seawater
%
% Inputs:
% T : Temperature (K)
% S : Salinity (g/kg)
%
% Output:
% Cp : Specific Heat (kJ/kg.K)
%==========================================================

% -------- Validity Check --------
if T < 273.15 || T > 453.15
    error('Temperature must be between 273.15 K and 453.15 K');
end

if S < 0 || S > 180
    error('Salinity must be between 0 and 180 g/kg');
end

% -------- Coefficients --------

A = 5.328 ...
    - 9.76e-2*S ...
    + 4.04e-4*S.^2;

B = -6.913e-3 ...
    + 7.351e-4*S ...
    - 3.15e-6*S.^2;

C = 9.6e-6 ...
    - 1.927e-6*S ...
    + 8.23e-9*S.^2;

D = 2.5e-9 ...
    + 1.666e-9*S ...
    - 7.125e-12*S.^2;

% -------- Specific Heat --------

Cp = A ...
    + B.*T ...
    + C.*T.^2 ...
    + D.*T.^3;

end