/***************************************************************************
                 module classe sbcgyre_utau_vtau.h  -  description
***************************************************************************/
// Mohamed Berrada
// locean-ipsl.upmc, Paris, Mars 18, 2009
//===========================================================================
//                          methode forward
forward ()
{ /* verification norm(xY-xF),norm(xY-xF)/norm(xF)
   utau   6.368455529132161e-16,     3.809412027961928e-16
   vtau   6.451334920495171e-16,     3.858987902188287e-16
*/
  if(Yt==TU){
    YS1=0.;
    YS2=0.;
  }
  else{
    //      !accumulates days of previous months of this year
    //      ! day (in hours) since january the 1st
    /*    double  ztime = float(Yt-TU)*rdt/(rmmss*rhhmm)//  ! incrementation in hour
	  - (nyear - 1) * rjjhh * raajj;//         !  - nber of hours the precedent years */
    double  ztime =  kt*rdt/(rmmss*rhhmm)//  ! incrementation in hour
      - (nyear - 1) * rjjhh * raajj;//         !  - nber of hours the precedent years
    double  ztimemax = ((5.*30.)+21.)* 24.;//               ! 21th june     in hours
    double  ztimemin = ztimemax+rjjhh*raajj/2.;//      ! 21th december in hours
    //      !                                            ! NB: rjjhh * raajj / 4 = 1 seasonal cycle in hours
    
    //      ! mean intensity at 0.105 ; srqt(2) because projected with 45deg angle
    double  ztau = 0.105/sqrt(2.);
    //      ! seasonal oscillation intensity
    double  ztau_sais = 0.015;
   
    double  ztaun = ztau-ztau_sais*cos((ztime-ztimemax)/(ztimemin-ztimemax)*rpi);
   

    //           ! domain from 15deg to 50deg and 1/2 period along 14deg
    //           ! so 5/4 of half period with seasonal cycle
    YS1 = - ztaun*sin(rpi*(gphiu(Yi,Yj)-15.)/(29.-15.));
    YS2 =   ztaun*sin(rpi*(gphiv(Yi,Yj)-15.)/(29.-15.));
  
    //JUL A MODIFIER APRES TEST
    //    YS1= 2;
    //YS2=0;
    //FIN MODIF JUL
  }
  //
}

//===========================================================================
//                         methode  backward

backward ()
{
  
}

//===========================================================================
//********************* FIN DU MODULE sbcgyre_utau_vtau **********************