%  function MTSPT = calc_MTSPT(Ts1,Ts2,Ta1,Ta2)
%
% Computes moisture transport (in kg/s) 

   function MTSPT = calc_MTSPT(Ts1,Ts2,Ta1,Ta2)
       
     % Read Parameter
     TwoBox_Param;
    
     % Atm.  circulatio strength
     [PSIa,PSIo] = calc_Psi(Ts1,Ts2); %in kg/s NB: PSIo not needed here

     % Computes (low level) specific humidity 
     Pa = 750; %low level pressure (mb)
     RHa = 0.6; %relative humidity at Pa
     [Esat,Qsat1] = Clausius_Clapeyron((Ts1+Ta1)/2,Pa);
     Qa1 = RHa * Qsat1; %in kg/kg
     [Esat,Qsat2] = Clausius_Clapeyron((Ts2+Ta2)/2,Pa);
     Qa2 = RHa * Qsat2; %in kg/kg
     
     % Moisture transport
     MTSPT = PSIa * (Qa1-Qa2);