COMODO, Evaluation of numerical methods for Ocean Modeling Yves Soufflet, Florent Lyard, Laurent Debreu, Patrick Marchesielo ...and more LEGOS, Toulouse IMUM 2014, Lisbon http://www.comodo-ocean.fr 1/20 The Comodo Project 7 labs 7 tasks • Dissipation mechanisms • Momentum advection • Ifremer, LPO, LEGOS, LEGI, INRIA, SHOM, LOCEAN, LA schemes • Time integrators 6 Models • Tracers advection-diffusion MARS, NEMO, ROMS, Symphonie, HYCOM, TUGO • Vertical coordinate systems • Unstructured mesh methods • Non hydrostatic http://www.comodo-ocean.fr 1 common tool: pycomodo library (Marc Honnorat INRIA) 2/20 The Comodo Project http://www.comodo-ocean.fr 3/20 The Comodo Project http://www.comodo-ocean.fr 4/20 7 Testcases • Baroclinic Vortex Momentum scheme and dispersion • Eddy topography iteraction Topographic rectification, PV and enstrophy conservation • Thacker bbl and adiabatic flow along topography • Upwelling bottom flow and vertical coordinates • Internal Wave • Lock Exchange spurious diapycnal diffusion • Baroclinic Jet Effective model resolution http://www.comodo-ocean.fr 5/20 Internal Wave Objectives configuration • Validate the pressure gradient calculation, • Sensitivity of the generation and propagation of IW, • Investigate the effective resolution in relationship to horizontal and vertical resolution, • Address the extension toward non-hydrostatic methods, http://www.comodo-ocean.fr • Test outgoing OBC for baroclinic fields in hydrostatic and non-hydrostatic dynamics 6/20 Internal Wave with Tugo http://www.comodo-ocean.fr 7/20 Lock Exchange Objectives configuration • Quantification of the spurious diapycnal mixing • Investigate the accuracy of advection schemes • Impact of numerical choices on numerical solution • Setup following Haidvogel and Beckman, Burchard and Rennau 2008 • Diagnostics based on Illicak (OM 2012), RPE , density class and front location http://www.comodo-ocean.fr 8/20 Lock Exchange in Fluidity-ICOM http://www.comodo-ocean.fr 9/20 Baroclinic Jet: Surface Vorticity and KE Spectrum http://www.comodo-ocean.fr 10/20 ROMS NEMO comparison, Surface Vorticity Figure: Colorbar symetric from -0.00015 to 0.00015 http://www.comodo-ocean.fr 11/20 Profiles Figure: 20 years average profiles for ROMS (plain line) and NEMO (dashed) http://www.comodo-ocean.fr 12/20 ROMS NEMO comparison: KE spectra Figure: 20 years average spectra at 10m depth for ROMS (plain line) and NEMO (dashed) http://www.comodo-ocean.fr 13/20 Injection <w’b’> at different resolution Figure: Injection Spectra at 10m http://www.comodo-ocean.fr 14/20 Diffusion at different resolution • Amount of dissipation decrease with resolution • Dissipation range is also reduced towards small scale http://www.comodo-ocean.fr 15/20 Transfert at different resolution • Direct cascade in the dissipative range http://www.comodo-ocean.fr 16/20 Barotropic/baroclinic coupling filter • Effect of temporal filter: spectra for 5 Km resolution at 10m • No effect at small scales http://www.comodo-ocean.fr 17/20 Effect of Diapycnal mixing • ROMS run with RSUP3-ISO: Rotation of diffusion tensor • Extension of the injection range at small scales http://www.comodo-ocean.fr 18/20 Profiles at 5km • Large effect of diapycnal mixing at the surface • Preserving the stratification allows more APE to be converted http://www.comodo-ocean.fr 19/20 Final word The baroclinic Jet • Spectral budget help to identify sources of dissipation Other test cases • Looking for volunteers... • Which test case can YOU do? • Difficult to point exactly to the source of differences between model • Clear/important role of the diffusion of tracer http://www.comodo-ocean.fr 20/20