!====================== include file "tbt.h" ===========================

!     ntbtts = number of tracer term balance time steps

!     tbt   = time averagred term balances of tracers
!       (1) = total time rate of change for the tracer
!       (2) = change due to zonal nonlinear term (UT)x
!       (3) = change due to meridional nonlinear term (VT)y
!       (4) = change due to vertical nonlinear term (WT)z
!       (5) = change due to zonal diffusion: Ah*Txx
!       (6) = change due to meridional diffusion: Ah*Tyy
!       (7) = change due to vertical diffusion:  kappa_h*Tzz
!       (8) = change due to source term
!       (9) = change due to explicit convection
!      (10) = change due to filtering
!      (11) = average tracer within volume (tracer units)
#if defined O_mom_tbt

      integer ntbtts
      common /tbt_i/ ntbtts

      real tbt, tbtsf
      common /tbt_r/ tbt(imt,jmt,km,nt,11), tbtsf(imt,jmt,nt)
#endif