= NEMO Release notes Last edition: '''[[Wikinfo(changed_ts)]]''' by '''[[Wikinfo(changed_by)]]''' [[PageOutline(2, , inline, unnumbered)]] {{{#!comment TO BE ADDED (was before 3.2 but version to be checked): transition to full native FORTRAN 90, deep code restructuring and drastic reduction of CPP keys ; introduction of partial step representation of bottom topography [Barnier et al. 2006, Le Sommer et al. 2009, Penduff et al. 2007] ; partial reactivation of a terrain-following vertical coordinate (s- and hybrid s-z) with the addition of several options for pressure gradient computation 5 ; more choices for the treatment of the free surface : full explicit, split-explicit or filtered schemes, and suppression of the rigid-lid option ; non linear free surface associated with the rescaled height coordinate z* or s; additional schemes for vector and flux forms of the momentum advection ; additional advection schemes for tracers ; online diagnostics : tracers trend in the mixed layer and vorticity balance ; rewriting of the I/O management with the use of an I/O server ; generalized ocean-ice-atmosphere-CO2 coupling interface, interfaced with OASIS 3 coupler ; surface module (SBC) that simplify the way the ocean is forced and include two bulk formulea (CLIO and CORE) and which includes an on-the-fly in- terpolation of input forcing fields ; major changes in the TKE schemes : it now includes a Langmuir cell parametrization [Axell 2002], the Mellor and Blumberg [2004] surface wave breaking parametrization, and has a time discretization which is energeti- cally consistent with the ocean model equations [Burchard 2002, Marsaleix et al. 2008] ; tidal mixing parametrisation (bottom intensification) + Indonesian specific tidal mixing [Koch-Larrouy et al. 2007] ; }}} == 2015 v3.6 stable (CMIP6) ==== Main new features * Coupled interface for next IPCC requirements (multi category sea-ice, calving and iceberg module) * Runoff improved and SBC with BGC * Solar flux filtering at daily frequency to force BGC component * Major evolution of LIM sea-ice model (including LIM3 in mono category, i.e. similar to LIM2) * On line coarsening of ocean I/O * Ocean and ice allowed to be explicitly coupled through OASIS, using !StandAlone Surface module) * First steps of wave coupling * MPI optimisation * XIOS new IO system * Standard Fox Kemper parametrisation * Atmospheric forcing at land-ocean interface * Open boundaries: completion of BDY/OBC merge * Solved 2 time stepping issues * Faster split-explicit time stepping, Z-tilde ALE coordinates, implicit bottom friction * First version of Configuration Manager * Standalone OBS component and improvements in OBS & ASM ==== Features becoming obsolete * LIM2 (replaced by LIM3 monocategory) ==== List of associated branches * [source:/branches/2015/dev_r5003_MERCATOR6_CRS/ Online biogeochemistry coarsening] == 2014 v3.6 Includes all the developments of 3_5 (especially the new XIOS IO system) , and new features: * Open boundaries: completion of BDY/OBC merge * Solved 2 time stepping issues * Faster split-explicit time stepping, Z-tilde ALE coordinates, implicit bottom friction * First version of Configuration Manager * Major evolution of LIM sea-ice model (including towards LIM2/LIM3 merge) * Standalone OBS component and improvements in OBS&ASM * Coupled interface for next IPCC requirements (multi category sea-ice, calving and iceberg module) * Runoff improved and SBC with BGC * MPP assessment and optimisation * Standard Fox Kemper parametrisation * First steps of wave coupling * On line coarsening of ocean I/O * Solar flux filtering at daily frequency to force BGC component * Atmospheric forcing at land-ocean interface == 2012 v3.5 Brief overview of the v3_5_alpha majors improvements and developments The new !Input/Output server XIOS is a major evolution including a versatile xml interface, the dedicated processors for I/O functionality allowing improved scalability, and a large performance improvement on massively parallel platforms.\\ This option is now set as the default one. The previous IOIPSL code and interface are kept as backup options at this stage. === Interfaces * Ocean/ice/biogeochemistry/atmosphere: revisit heat/salt(tracers)/mass fluxes ; new levitating & embedded sea-ice (for LIM & CICE) * AGRIF is now sea-ice (LIM) compatible using a new AGRIF package shared with other GCMs * Compilation with external biogeochemistry model * Improved CICE-NEMO interface * ICB module (Bigg et al 1997, Martin and Adcroft 2010): icebergs as lagrangian floats (~200,000!) allowing improved fresh water input especially in the Southern ocean * SAS: Stand Alone Surface module allowing testing of forcing set with bulk formulae, to run sea-ice models without ocean, to run ICB icebergs module alone, and to test AGRIF with sea-ice * Biogeochemical component NEMO-TOP: PISCES will now include the LOBSTER functionalities, becoming more general and allowing a simplification and reduction of code size * Open boundaries module: merging the two existing options (OBC and BDY) has made some important progress (end of the work expected for 2013) * Wave-NEMO interface module has been further developed with the introduction of the reading of the 2D stoke drift and wave number and the on-line computation of the 3D stoke drift current. === Misc. * A new vertical sigma coordinate stretching function (Siddorn and Furner OM 2012r) * Smagorinsky eddy coefficients: Smagorinsky type diffusivity/viscosity for lateral mixing has been introduced * Analytical tropical cyclones taken in account using track and magnitude observations (Vincent et al. JGR 2012a,b) * MUSCL: an option for local up-stream advection schemes which are useful in case of rivers, straits and in proximity of open lateral boundary conditions. The possibility to switch from MUSCL to a standard up-stream scheme has been included in the MUSCL advection routine * NEMO-OBS: observation operators. Add a model equivalent of SST at night * Log layer for bottom friction is now added (sigma coordinates only) * Evolution of SETTE validation tool == 2011 v3.4 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 * Completion of Griffies iso-neutral diffusion * Back to a semi-implicit bottom friction * Add Pacanowski-Philander scheme for computation of Ekman depth * Add a new bulk formulae (so called MFS) * Introduce a drag coefficient compute by wave model * Add tidal potential forcing * Netpune effect parametrization * Point to point MPI communication for north fold * Allow sub timestepping for biogeochemistry models when using non-linear free surfac * 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 * Improvement of format for lagrangian floats * Online computing of transport across sections * Tidal harmonic analysis * Tools to prepare input files for observation operator * Timing functionality ==== 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 == 2010 v3.3 * Introduction of a modified leapfrog-Asselin filter time stepping scheme [Leclair and Madec 2009] ; * Additional scheme for iso-neutral mixing [Griffies et al. 1998], although it is still a ”work in progress” ; * Rewriting of the bottom boundary layer scheme, following Campin and Goosse [1999] ; * Addition of a Generic Length Scale vertical mixing scheme, following Um- lauf and Burchard [2003] ; * Addition of the atmospheric pressure as an external forcing on both ocean and sea-ice dynamics ; * Addition of a diurnal cycle on solar radiation [Bernie et al. 2007] ; river runoffs added through a non-zero depth, and having its own temperature and salinity ; * CORE II normal year forcing set as the default forcing of ORCA2-LIM configuration ; * Generalisation of the use of fldread.F90 for all input fields (ocean climatology, sea-ice damping...) ; * Addition of an on-line observation and model comparison (thanks to NEMOVAR project) ; * Optional application of an assimilation increment (thanks to NEMOVAR project) ; * Coupling interface adjusted for WRF atmospheric model ; * C-grid ice rheology now available for both LIM-2 and LIM-3[Bouillon et al. 2009] ; * LIM-3 ice-ocean momentum coupling applied to LIM-2 ; * Deep re-writting and simplification of the off-line tracer component (OFF SRC) ; * Merge of passive and active advection and diffusion modules ; * Use of the Flexible Configuration Manager (FCM) to build configurations, generate the Makefile and produce the executable ; * Linear-tangent and Adjoint component (TAM) added, phased with v3.0 In addition, several minor modifications in the coding have been introduced with the constant concern of improving the model performance. == 2009 v3.2 ''This release has been mainly designed for climate models, with enhanced coupling interface and implementation of AR5 diagnostics.'' === New science * Tidal mixing parametrization (bottom intensification) + Indonesian specific tidal mixing * RGB light penetration and optional use of ocean color * VVL option has been restored, including revisit free-surface time-splitting algorithm to reach stability and satisfying result, available for all type of coordinates (z, zps, s) * TKE change in the surface boundary condition, especially in coupled mode (mean stress module send by the atmosphere) === New High Performance Computing * Way to handle outputs has been improved * Implementation of IOM for output with the following functionalities : allows to output at few frequencies during same simulation, e.g both monthly and daily; output vectors/scalars is also available (for a strait transport calculation or for a vertical profile associated to buoys location for instance), and make easier the way to add an output everywhere in the code * Suppression of rigid-lid option and no more island specific treatment * Cleaning of lib_mpp * SHMEM option has been removed * North fold treatment is now done once for all in a new routine lbcnfd.F90 instead of being duplicated * Suppression of redundant east-west communication phase (ORCA grid case) == 2008 v3.1 === New science * Open Boundaries BDY package as unstructured boundaries, and OBC package entirely cleaned and documented, * New TKE physics * New sea-ice NEMO-LIM 3.0 (key_lim3) component including: ice-thickness categories, EVP rheology on C-Grid, ice salinity variations interfaced with the new surface module === New High Performance Computing * New surface module in NEMO-OPA * Namelists entire re-organisation, improve readability and coherence * Improvement of IOManager now able to handle long simulations and so to manage successive input files from one year to an other * Improvements of AGRIF performance and users interface * Improved vectorial performances (~5%) of the rheology module in LIM 2.0 * TOP reorganisation with one directory by model Fully written in Fortran 90, include all SMS models ( PISCES, LOBSTER, CFC ...) and interface for users development through the MY_TRC directory) * Update IOM modules for OFFLINE tracers * Interpolation On the Fly * Passive tracers used with AGRIF package == 2007 v2.3 === New science * Implement non linear free surface (variable volume) * Implement Kriest parametrization in NEMO-TOP * Implement AGRIF 2 ways nesting for passive tracers * Implement quickest scheme for tracers === New High Performance Computing == 2005-2006 v2.0 === New science * Add the 1D configuration option * KPP turbulent closure scheme implementation * Implement CFC tracers and p4z * Add new surface pressure gradient algorithms and its interface to Open Boundary Conditions module * First implementation of AGRIF 2 ways nesting tool * Implement overturning computation for main basins * Implement ice damping in buffer zones * Implement 1D on-line & off-line passive tracers * Implement new tracers advection scheme UBS * Implement computation of mean trends in the mixed layer taking into account the asselin time filter === New High Performance Computing * Implementation of a hierarchy of debugging levels * Rewriting of NEMO-TOP biogeochemistry component * Remove some of the bio models (p3zd,npzd, hamocc3, age, gosac) * Switch to IOIPSL-3-0 new input output library * Switch rigid lid to option rather than default * Re-organization of coordinate definition, scale factors are now 3d by default, include file for partial steps has been removed * Implement IO Manager module * Enables bit comparison between single and multiple processor runs * Implement OASIS3 and OASIS4 interfaces to buid coupled ocean-atmosphere configurations