[[PageOutline]]
Last edited [[Timestamp]]

[[BR]]

'''Author''' : Clement BRICAUD and Guillaume Reffray 

'''ticket''' : #687

'''Branch''' : [https://forge.ipsl.jussieu.fr/nemo/browser/branches/DEV_r1784_GLS ] 
----

=== Description ===
Implementation of the vertical scheme:
Mellor Yamada 2,5, generic length scale (Umlauf and burchard 2003) +boundary conditions(Craig and Banner) 

It is activated by CPP key : key_zdfgls


----

=== Testing ===
Testing could consider (where appropriate) other configurations in addition to NVTK].

||NVTK Tested||!'''YES!'''||
||Other model configurations||!'''YES!'''||
||Processor configurations tested||[ 1*2 2*1 2*2 ]||
||If adding new functionality please confirm that the [[BR]]New code doesn't change results when it is switched off [[BR]]and !''works!'' when switched on||!'''YES!'''||



=== Bit Comparability ===
||Does this change preserve answers in your tested standard configurations (to the last bit) ?||!'''NO !'''||
||Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended)||!'''NO!'''||
||Is this change expected to preserve answers in all possible model configurations?||!'''NO!'''||
||Is this change expected to preserve all diagnostics? [[BR]]!,,!''Preserving answers in model runs does not necessarily imply preserved diagnostics. !''||!'''NO!'''||

If you answered !'''NO!''' to any of the above, please provide further details:
It is an alternative option for TKE
 
----
=== System Changes ===
||Does your change alter namelists?||!'''YES !'''||
||Does your change require a change in compiler options?||!'''NO !'''||

The is a dedicated bloc for gls scheme in namelist:

!-----------------------------------------------------------------------

&namzdf_gls                !   GLS vertical diffusion  ("key_zdfgls")

!-----------------------------------------------------------------------

   rn_emin     =   1.e-6   !  minimum value of e   [m2/s2]

   rn_epsmin   =   1.e-12  !  minimum value of eps [m2/s3]

   ln_length_lim = .true.  !  limit on the dissipation rate under stable stratification (Galperin et al., 1988)

   clim_galp   =   0.53    !  galperin limit

   ln_crban = .TRUE.       !  Use Craig & Banner (1994) surface wave mixing parametrisation

   ln_sigpsi = .TRUE.      !  Activate or not Burchard 2001 mods on psi schmidt number in the wb case

   rn_crban = 100.         !  Craig and Banner 1994 constant for wb tke flux

   rn_charn =  70000.      !  Charnock constant for wb induced roughness length

   nn_tkebc_surf  =   1    !  surface tke condition (0/1/2=Dir/Neum/Dir Mellor-Blumberg)

   nn_tkebc_bot   =   1    !  bottom tke condition (0/1=Dir/Neum)

   nn_psibc_surf  =   1    !  surface psi condition (0/1/2=Dir/Neum/Dir Mellor-Blumberg)

   nn_psibc_bot   =   1    !  bottom psi condition (0/1=Dir/Neum)

   nn_stab_func   =   2    !  stability function (0=Galp, 1= KC94, 2=CanutoA, 3=CanutoB)

   nn_clos        =   1    !  predefined closure type (0=MY82, 1=k-eps, 2=k-w, 3=Gen)

/
!-----------------------------------------------------------------------


----
=== Resources ===
There is no change for runtime.

For memory: memory is 1.04 more than reference configuration for ORCA2_LIM.


----
=== IPR issues ===
||Has the code been wholly (100%) produced by NEMO developers staff working exclusively on NEMO?||!'''YES !'''||