anchor.diff:    !     ================
     !     kw660   = gas transfer velocity (piston velocity) for CO2 [m/s] 
     !               without T-dependant Schmidt number correction
  -  !               but accounting for sea ice fraction (See OCMIP2 design & HOWTO documents for details)
  +  !               BUT accounting for sea ice fraction (See OCMIP2 design & HOWTO documents for details)
     !     xco2    = atmospheric mole fraction of CO2 [ppm]
     !     Patm    = atmospheric pressure at surface [atm]
     !     dz1     = depth of the top vertical layer of the model [m]
  
positive.code:   RETURN
  END SUBROUTINE vapress
  
  END MODULE gasx
  
negative.code:    IMPLICIT NONE
  
  !  Input & output variables:
     REAL(kind=r8), INTENT(in) :: Tc
     REAL(kind=r8) :: sco2
  
     sco2 = 1920.4 - 135.6*Tc  + 5.2122*Tc**2 - 0.10939*Tc**3  + 0.00093777*Tc**4
  
     RETURN
  END FUNCTION sco2
  