Tracer/Dynamics Trends (namtrd)

!-----------------------------------------------------------------------
&namtrd        !   diagnostics on dynamics and/or tracer trends
!              !       and/or mixed-layer trends and/or barotropic vorticity
!-----------------------------------------------------------------------
   ln_glo_trd  = .false.   ! (T) global domain averaged diag for T, T^2, KE, and PE
   ln_dyn_trd  = .false.   ! (T) 3D momentum trend output
   ln_dyn_mxl  = .FALSE.   ! (T) 2D momentum trends averaged over the mixed layer (not coded yet)
   ln_vor_trd  = .FALSE.   ! (T) 2D barotropic vorticity trends (not coded yet)
   ln_KE_trd   = .false.   ! (T) 3D Kinetic   Energy     trends
   ln_PE_trd   = .false.   ! (T) 3D Potential Energy     trends
   ln_tra_trd  = .FALSE.   ! (T) 3D tracer trend output
   ln_tra_mxl  = .false.   ! (T) 2D tracer trends averaged over the mixed layer (not coded yet)
   nn_trd      = 365       !  print frequency (ln_glo_trd=T) (unit=time step)
/

Each trend of the dynamics and/or temperature and salinity time evolution equations can be send to trddyn.F90 and/or trdtra.F90 modules (see TRD directory) just after their computation ($i.e.$ at the end of each $dyn\cdots.F90$ and/or $tra\cdots.F90$ routines). This capability is controlled by options offered in namtrd namelist. Note that the output are done with xIOS, and therefore the key_ IOM is required.

What is done depends on the namtrd logical set to true:

ln_glo_trd

: at each nn_trd time-step a check of the basin averaged properties of the momentum and tracer equations is performed. This also includes a check of $T^2$, $S^2$, $\tfrac{1}{2} (u^2+v2)$, and potential energy time evolution equations properties ;

ln_dyn_trd

: each 3D trend of the evolution of the two momentum components is output ;

ln_dyn_mxl

: each 3D trend of the evolution of the two momentum components averaged over the mixed layer is output ;

ln_vor_trd

: a vertical summation of the moment tendencies is performed, then the curl is computed to obtain the barotropic vorticity tendencies which are output ;

ln_KE_trd

: each 3D trend of the Kinetic Energy equation is output ;

ln_tra_trd

: each 3D trend of the evolution of temperature and salinity is output ;

ln_tra_mxl

: each 2D trend of the evolution of temperature and salinity averaged over the mixed layer is output ;

Note that the mixed layer tendency diagnostic can also be used on biogeochemical models via the key_ trdtrc and key_ trdmld_trc CPP keys.

Note that in the current version (v3.6), many changes has been introduced but not fully tested. In particular, options associated with ln_dyn_mxl, ln_vor_trd, and ln_tra_mxl are not working, and none of the option have been tested with variable volume ($i.e.$ key_ vvl defined).