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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):
https://www.sgmeet.com/osm2012/default.asp
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
DEADLINE:
7 OCTOBER 2011
Best,
Pierre De Mey
Abstract:
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 |
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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.
http://dx.doi.org/10.1016/j.ocemod.2010.09.006
About
POC:
The
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
g
Toulouse, April 2007.
Toulouse, january
2008. © Claudine Marsaleix
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Energy
transfers in internal tide generation, propagation and dissipation
in the deep ocean
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Floor
J.W., Auclair F., Marsaleix P., 2011 Ocean
Modelling
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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.
VIEW
AT PUBLISHER
What induced the exceptional 2005 convection event in
the northwestern Mediterranean basin? Answers from a modeling
study
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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
Photographs:
POC linux
cluster
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Aspects
of the seasonal variability of the Northern Current
(NW Mediterranean Sea) observed by altimetry
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F.
Birol, M. Cancet and C. Estournel
JMS 2010
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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.
doi:10.1016/j.jmarsys.2010.01.005
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