Forces on the fluid

Only the gravity is considered through the thermal buoyancy effect. The gravity force is oriented facing downward. 

 &Gravity Gravity_Enabled= .true.          ,     !--- the gravity force is enabled
          Gravity_Angle_IJ= 0.0            ,     !--- {IJ} angle (in degree unit)
          Gravity_Angle_IK= 90.0           ,     !--- {IK} angle (in degree unit)
          Reference_Gravity_Constant= 1.D+00/    !--- dimensionless value of g0
For more information on the gravity data set, see the Namelist "Gravity".