[[PageOutline]] Last edited [[Timestamp]] '''Author''' : Gurvan Madec, Florian Lemarié, George Nurser '''ticket''' : #1593 '''Branch''' : [https://forge.ipsl.jussieu.fr/nemo/browser/branches/2014/dev_r5721_CNRS9_NOC3_LDF 2015/dev_r5721_CNRS9_NOC3_LDF] '''WP2015 Action''' : CNRS-9 and NOC-3 ---- === Description === Development branch related to CNRS-9 and NOC-3 actions of 2015 work plan :[[BR]] • simplify and improve the tracer advection and the lateral diffusion and dissipation in NEMO/OPA[[BR]] • generalization of the use of surface scale factors (e1e2 at T, U, V, F points) NB: This development consists in merging the current trunk with the last year work on that subject (see ticket #1260, and the associated branch ​​2014/dev_CNRS0_NOC1_LDF​ and wiki page ​​1260_CNRS0_NOC1_LDF. ''Simplification'': [[BR]](1) define bi-laplacian diffusive operator on dynamics and tracers are re-entrant laplacian ;[[BR]](2) change the way the eddy diffusivity and viscosity are specified and controlled by the user ;[[BR]](3) generalize of the use of surface scale factors ;[[BR]](4) add a optional read of surface scale factors in coordinate file in case of reduction of the scale factors in some straits. ''Improvements'': [[BR]] (1) introduce Beckers et al. (2000) compact stencil in the cross-isoneutral direction in triads formalism ; [[BR]] (2) introduce in both iso-neutral operator the Method of Stabilizing Correction (Lemarié et al. (2012) ; [[BR]] (3) implement bilaplacian iso-neutral operator (Lemarié et al. (2012). ---- === Strategy === Three steps: I. '''Phasing of scale factors''' (I.0) standardisation of the name of surface scale factors (e1e2t, e1e2u, e1e2v, e1e2f) ;[[BR]](I.1) generalize of the use of surface scale factors ;[[BR]](I.2) add a optional read of surface scale factors in coordinate file in case of reduction of the scale factors in some straits. I. Phasing of the advective/diffusive trends on tracers (I.0) ... I. Phasing of viscous trends (I.0) ... ---- === Changes === ... ---- '''Testing''' Testing could consider (where appropriate) other configurations in addition to NVTK]. || NVTK Tested || !'''YES/NO!''' || || Other model configurations || !'''YES/NO!''' || || Processor configurations tested || [ Enter processor configs tested here ] || || 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/NO/NA!''' || (Answering UNSURE is likely to generate further questions from reviewers.) 'Please add further summary details here' * Processor configurations tested * etc---- === Bit Comparability === || Does this change preserve answers in your tested standard configurations (to the last bit) ? || !'''YES/NO !''' || || Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended) || !'''YES/NO!''' || || Is this change expected to preserve answers in all possible model configurations? || !'''YES/NO!''' || || Is this change expected to preserve all diagnostics? [[BR]]!,,!''Preserving answers in model runs does not necessarily imply preserved diagnostics. !'' || !'''YES/NO!''' || If you answered !'''NO!''' to any of the above, please provide further details: * Which routine(s) are causing the difference? * Why the changes are not protected by a logical switch or new section-version * What is needed to achieve regression with the previous model release (e.g. a regression branch, hand-edits etc). If this is not possible, explain why not. * What do you expect to see occur in the test harness jobs? * Which diagnostics have you altered and why have they changed?Please add details here........ ---- === System Changes === || Does your change alter namelists? || !'''YES/NO !''' || || Does your change require a change in compiler options? || !'''YES/NO !''' || If any of these apply, please document the changes required here....... ---- === Resources === !''Please !''summarize!'' any changes in runtime or memory use caused by this change......!'' ---- === IPR issues === || Has the code been wholly (100%) produced by NEMO developers staff working exclusively on NEMO? || !'''YES/ NO !''' || If No: * Identify the collaboration agreement details * Ensure the code routine header is in accordance with the agreement, (Copyright/Redistribution etc).Add further details here if required..........