= NEMO 3.4 release

Original publication (eZ): '''2013-02-13 17:44 CET''' by '''clevy'''\\
Last edition: '''[[Wikinfo(changed_ts)]]''' by '''[[Wikinfo(changed_by)]]'''

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The new release 3.4 of NEMO is now available.

Note this is a major release and the documentation has been updated in consequence.

== Major improvements

=== New physics and numerics

* New pressure gradient suitable for s-coordinate (namelist ln_hpg_djc)
* Completion of Griffies iso-neutral diffusion (ln_traldf_grif)
* Back to a semi-implicit bottom friction (bugfree) (namelist ln_bfrimp)
* Add Pacanowski-Philander scheme for computation of Ekman depth in zdfri
* Add a new bulk formulae (namelist ln_blk_mfs and &namsbc_mfs)
* Introduce a drag coefficient compute by wave model (new namelist &namsbc_wave)
* Add tidal potential forcing (new namelist &nam_tide)
* Neptune effect parametrization
* Point to point MPI communication for north fold (namelist ln_nnogather)
* Allow sub timestepping for biogeochemistry models when using non-linear free surface
* Improvement in PISCES (light limitation ; quota model for iron ; use Pa in gas exchange ; fldread for all data ; calcite dissolution & calcon salinity dependence)

=== Configurations, diagnostics and tools

* Suppression of POMME configuration
* Addition of a regional configuration AMM12 (key_amm_12km and [http://prodn.idris.fr/thredds/catalog/ipsl_public/reee451/NEMO/catalog.html?dataset=DatasetScanipsl_public/reee451/NEMO/amm12_inputs_v3_4.tar input files])
* Improvement of format for lagrangian floats
* Online computing of transport across sections
* Tidal harmonic analysis (new namelist &nam_diaharm)
* Tools to prepare input files for observation operator
* Timing functionality (namelist ln_timing)

=== System simplification

* Simplification of dynamic allocation
* End of merge TRA/TRA (no more separate 3d arrays for tracers, only 4d)
* Suppression of obsolete hpg options
* More flexible definition of BDY input data
* Simplification of interfaces toward biogeochemical models 
* Interface with CICE in coupled mode
* Use of fldread to read/interpolate data for passive tracers and dynamical input data for OFFLINE configurations