!  $Id$



#undef WHERE
#undef ELSEWHERE
#undef ENDWHERE

#ifdef SCALAR
#define WHERE(A)  if(A) then
#define ELSEWHERE else
#define ENDWHERE  endif
#else
#define WHERE     where
#define ELSEWHERE elsewhere
#define ENDWHERE  endwhere
#endif      

      real :: URAMP


      if(present(RAMP)) then
         URAMP = -RAMP
      else
         URAMP = TMIX
      end if

      T   = MAX(MIN(TL-ZEROC,TMAX),TMIN)


      WHERE(T.LT.TSTARR1)
       QX = (T*(T*(T*(T*(T*(T*S16+S15)+S14)+S13)+S12)+S11)+S10)
      ENDWHERE

      WHERE(T.GE.TSTARR1.AND.T.LT.TSTARR2)
       W = (TSTARR2 - T)/(TSTARR2-TSTARR1)
       QX =     W *(T*(T*(T*(T*(T*(T*S16+S15)+S14)+S13)+S12)+S11)+S10) &
          + (1.-W)*(T*(T*(T*(T*(T*(T*S26+S25)+S24)+S23)+S22)+S21)+S20)
      ENDWHERE

      WHERE(T.GE.TSTARR2.AND.T.LT.TSTARR3)
       QX = (T*(T*(T*(T*(T*(T*S26+S25)+S24)+S23)+S22)+S21)+S20)
      ENDWHERE

      WHERE(T.GE.TSTARR3.AND.T.LT.TSTARR4)
       W = (TSTARR4 - T)/(TSTARR4-TSTARR3)
       QX =     W *(T*(T*(T*(T*(T*(T*S26+S25)+S24)+S23)+S22)+S21)+S20) &
          + (1.-W)*(T*(T*(T*(T*(T*(T*BI6+BI5)+BI4)+BI3)+BI2)+BI1)+BI0)
       ENDWHERE

      WHERE(T.GE.TSTARR4.AND.T.LE.0)
       QX = (T*(T*(T*(T*(T*(T*BI6+BI5)+BI4)+BI3)+BI2)+BI1)+BI0)
      ENDWHERE

      if(URAMP < 0.0) then
         WHERE(T.GE.URAMP.AND.T.LE.0.)
            W = (URAMP - T)/URAMP
            QX =       W *(T*(T*(T*(T*(T*(T*B6+B5)+B4)+B3)+B2)+B1)+B0)        &
                 + (1.-W)*QX
         ENDWHERE
      end if

      WHERE(T.GT.0.)
       QX = (T*(T*(T*(T*(T*(T*B6+B5)+B4)+B3)+B2)+B1)+B0)
      ENDWHERE

      if(present(PASCALS)) then
         if(PASCALS) QX = QX * 100.
      end if

      D = (PL - ERFAC*QX)

      WHERE(D.LE.0.)
       QSAT = MAX_MIXING_RATIO
      ELSEWHERE
       QSAT = MIN(QX / D,MAX_MIXING_RATIO)
      ENDWHERE

      RETURN