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 ( at the end of each and/or 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 , , , 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 ( key_ vvl defined).

Gurvan Madec and the NEMO Team

NEMO European Consortium2017-02-17