Pôle Océan & Couplages
de l'Observatoire Midi-Pyrénées
CNRS & Université de Toulouse
14 Avenue Edouard Belin
31400 Toulouse - France

OBJECTIVES: To improve the knowledge of oceanic processes in diversified regions by

  • studying their spatial and temporal
  • quantifying them
  • assessing the interactions
    between elementary
  • developing forecasting
  • GEneric MOdelling

AGU 2012
Ocean Sciences meeting

Dear colleagues,

On behalf of the session 6 organizers, I would like to invite you to submit an abstract in the TOS/ASLO/AGU 2012 Ocean Sciences meeting (20-24 Feb. 2012, Salt Lake City, Utah, U.S.A):


on the session:

006: Advances in Coastal Ocean Modeling, Analysis, and Prediction

(see abstract below) which is is linked to four topic categories:

#2 Physical Oceanography and Limnology
#6 Nearshore and Coastal Regions
#13 Observatories, Observational Oceanography, new Technology
#14 Oil spill, Gulf of Mexico



Pierre De Mey


Downscaling and extending predictability in coastal and
shelf seas are two of the objectives of the GODAE OceanView (GOV) initiative through its Coastal Ocean and Shelf Seas Task Team (COSSTT). Broad participation and international coordination of interdisciplinary coastal and shelf models nested in data assimilative large scale models is a COSSTT priority. This session will provide a forum for multi-scale hydrodynamic modeling and observational studies that aim toward scientific validation, prediction and operational applications of numerical models in coastal and shelf seas, leading to new understanding of multiscale nonlinear ocean processes. Applications of nested models, such as the influence of physical processes on ecosystem dynamics and interdisciplinary coastal predictions are also welcome. The session will promote the discussion of methodologies that lead to reliable coastal forecasts (such as data assimilation, error analysis, influence of nesting, resolution and forcing), Observing System Simulation Experiments and the impact of sustainable, integrated modeling and observational networks that connect local, regional and global scales. Applications on lessons learned from prediction and/or hindcasts during the 2010 Deepwater Horizon oil spill in the Gulf of Mexico and the 2011 tsunami in Japan are particularly welcome.

/Organizers: /Villy Kourafalou, University of Miami/RSMAS, vkourafalou@rsmas.miami.edu; Pierre De Mey, LEGOS - Laboratoire d'Etudes en Geophysique et Oceanographie Spatiales,demey-redir@neyak.org;
Ruoying He, North Carolina State University,rhe@ncsu.edu; Alex Kurapov, Oregon State University,kurapov@coas.oregonstate.edu


Pierre De Mey

email: demey-redir@neyak.org
phone: +33(0)561332928
fax: +33(0)561253205
Associate Editor, Ocean Dynamics
Co-chair, GODAE OceanView Coastal and Shelf Seas Task Team (COSS-TT)
LEGOS - Laboratoire d'Etudes en Géophysique et Océanographie Spatiales
18 avenue Edouard Belin, 31401 Toulouse Cedex 9

A non-hydrostatic algorithm for free-surface ocean modelling

Auclair F., Estournel C., Floor J. W., Herrmann M., Nguyen C., Marsaleix P.
Ocean Modelling 2011

       An original implementation of a non-hydrostatic, free-surface algorithm based on a pressure correction method is proposed for ocean modelling. The free surface is implemented through an explicit scheme combined with a mode-spitting method but the depth-averaged velocity and the position of the free surface are updated at each non-hydrostatic iteration. The vertical momentum equation is also integrated up to the surface enabling a natural and accurate treatment of the surface layer. The consistent specification of the numerical schemes provides balanced transfers of potential and kinetic energy. This algorithm is well-suited for implementation as a non-hydrostatic kernel on originally hydrostatic free-surface ocean models such as Symphonie for which it has originally been developed. Energy balances associated with the propagation of short surface waves and solitary waves are presented for two dedicated well-documented configurations over closed domains. The buoyancy flux, the work rate of the pressure force together with the power of the advective terms are evaluated and discussed for the generation and the propagation of these two types of waves. The dissipation rate is in particular shown to be several orders of magnitude smaller than the work rates of the hydrostatic and non-hydrostatic pressure forces confirming the necessity for the exchanges of energy to be numerically balanced. The algorithm is subsequently applied to the complex generation of non-linear solitary internal waves by surface tides over Georges Bank, in the Gulf of Maine. The generation and the propagation of the observed non-linear and non-hydrostatic features in this region are correctly reproduced.

About POC:

he POC group has been created in 2001 by scientists from LEGOS and LA. One of the main objectives of POC is to study the oceanic circulation at regional and coastal scales. The approach is essentially... read the following

Toulouse, April 2007.

Toulouse, january 2008. © Claudine Marsaleix

Energy transfers in internal tide generation, propagation and dissipation in the deep ocean
Floor J.W., Auclair F., Marsaleix P., 2011 Ocean Modelling

The energy transfers associated with internal tide (IT) generation by a semi-diurnal surface tidal wave impinging on a supercritical meridionally uniform deep ocean ridge on the f-plane, and subsequent IT-propagation are analysed using the Boussinesq, free-surface, terrain-following ocean model Symphonie. The energy diagnostics are explicitly based on the numerical formulation of the governing equations, permitting a globally conservative, high-precision analysis of all physical and numerical/artificial energy transfers in a sub-domain with open lateral boundaries.

What induced the exceptional 2005 convection event in the northwestern Mediterranean basin? Answers from a modeling study
Herrmann, M., F. Sevault, J. Beuvier, and S. Somot
JGR 2010

        Open-sea convection occurring in the northwestern Mediterranean basin (NWMED) is at the origin of the formation of Western Mediterranean Deep Water (WMDW), one of the main Mediterranean water masses. During winter 2004–2005, a spectacular convection event occurred, observed by several experimental oceanographers. It was associated with an exceptionally large convection area and unusually warm and salty WMDW. Explanations were proposed tentatively, relating the unusual characteristics of this event to the Eastern Mediterranean Transient (EMT) or to the atmospheric conditions during winter 2004–2005 in the NWMED. They could, however, not be supported until now. Here we used numerical modeling to understand what drove this convection event. The control simulation performed for the period 1961–2006 reproduces correctly the long-term evolution of the Mediterranean Sea circulation, the EMT, and the NWMED convection event of 2004–2005. Sensitivity simulations are then performed to assess the respective contributions of atmospheric and oceanic conditions to this event. The weakness of the winter buoyancy loss since 1988 in the NWMED prevented strong convection to occur during the 1990s, enabling heat and salt contents to increase in this region. This resulted in the change of WMDW characteristics observed in 2005. The strong buoyancy loss of winter 2004–2005 was responsible for the intensity of the convection observed this winter in terms of depth and volume of newly formed WMDW. The EMT did not fundamentally modify the convection process but potentially doubled this volume by inducing a deepening of the heat and salt maximum that weakened the preconvection stratification. http:/dx.doi.org/10.1029/2010JC006162


POC linux cluster

Aspects of the seasonal variability of the Northern Current (NW Mediterranean Sea) observed by altimetry
F. Birol, M. Cancet and C. Estournel
JMS 2010
     Altimetry has become a powerful tool to understand the dynamics of the deep-sea ocean circulation. Despite the technical problems encountered in the coastal zone by this observational technique, resulting in large data gaps in those areas, solutions already exist to mitigate this issue and to allow the retrieval of coastal information from existing altimetric data. Using some of these solutions, we have reprocessed a new set of 14.5 years of the TOPEX/Poseidon and Jason-1 satellite altimeter data over the Northwestern Mediterranean Sea, leading to a significant increase in the quantity of available data near coastlines. Time series of geostrophic surface velocity anomalies have been computed from the along-track altimeter sea level anomalies. In this paper, we evaluate the ability of these altimeter-derived currents to capture the main surface circulation features and the associated seasonal variability in the area of interest.

    In-situ ADCP current measurements are used to estimate the accuracy of altimeter geostrophic surface velocity anomalies at different locations on the shelf edge. The results indicate good qualitative altimeter performances at seasonal time scales, confirming that altimetry is reliable to observe synoptic variations of the Liguro–Provençal–Catalan Current System. The seasonal evolution of the shelf edge flow is then documented using results from satellite altimetry and from sea surface temperature (SST). The regional picture of the shelf edge circulation that emerges agrees fairly well with previous knowledge (the flow is much stronger during winter than during summer) but also reveals interesting aspects of the coastal current system: (1) the characteristics of the seasonal cycle observed appear highly consistent along the Northwestern Mediterranean shelf break, suggesting a continuous current from the Tyrrhenian to the Balearic Seas, (2) the relationship with the Balearic Current appears somewhat more complex and suggests that its evolution is controlled by another inflow contribution, at least in spring, (3) the seasonal variations of the shelf edge flow over a particular year can show large discrepancies with the averaged picture presented in this study, since large year to year differences are observed.

Atlantic ocean
Baptiste Mourre
Bay of Biscay
Caroline Ulses
Claire Dufau
Claude Estournel

Coastal altimetry
Cyril Nguyen
Data assimilation
Dense water formation
Florent Lyard
Francis Auclair
Gravity waves
Gulf of Fos
Gulf of Gascogne
Gulf of Lion
Ivane Pairaud
Jérome Bouffard
Job opportunities
Julien Lamouroux
Laurent Roblou
Marine Herrmann
Matthieu Le Henaff
Mediterranean sea
Model outputs analysis
Operationnal oceanography
Open Boundary Conditions
Patrick Marsaleix
Pierre De Mey
Poc news
Post doc
Réunions poc
River plume
Sea level
Sediment transport
Semi enclosed Bay
Shelf circulation
Slope circulation
Thierry Letellier
Three dimensional circulations
Wind curl

POC (Pôle Océan & Couplages) - Observatoire Midi-Pyrénées - 14 Avenue Edouard Belin - 31400 Toulouse - France