 not used

         p_half -- real, dimension(:,:,:)
             pressure at interface between model levels
             size(p_half,3) must = 1 + size(t,3)
             units = Pascals

         z_full -- real, dimension(:,:,:)
             height of the levels where t, q, u, v, tr are defined
             shape must conform to that of xi
             units = meters


         dtau_du  -- real, dimension(:,:)
         dtau_dv  -- real, dimension(:,:)
         dsens_datmos -- real, dimension(:,:)
         