Modelling the Adour plume with a 3D
hydrodynamic model
Anne-Marie Jégou, Franck Dumas, Pascal Lazure
(1) Ifremer Brest, Del/ao, BP 70, 29280 Plouzané, France
amjegou@ifremer.fr
Abstract
The Adour plume evolution is simulated over 1995 with a 3D hydrodynamic model forced with wind and thermal fluxes provided by a meteorological model (Arpege, Météo-France), the tide and the discharges of
the Loire, ( iironde and Adour rivers.
Résumé
Le comportement et l’évolution saisonnière du panache de l’Adour sont
étudiés au moyen d’un modèle hydrodynamique 3D du golfe de Gascogne. L’évolution du panache durant l’année 1995 est simulée en forçant
le modèle par les vents et flux issus du modèle météorologique Arpege de
Météo-France, la marée et les débits mesurés de la Loire, de la Gironde et
de l’Adour.
Introduction
Hydrology over the continental shelf along the French coast shows highly
\ ariable salinities due to an extended plume largely driven by winds. The
dynamic behaviour of the Loire and the Gironde have already been quite
well-documented and studied (Lazure & Jégou, 1998). At the time, the
computed domain of the model used covered the entire Atlantic shelf
from the French coast to the 200 m isobath and from 44°N to 49°N. In
order to take the Adour plume into account and assess the influence of
mesoscale circulation on the shelf, the model was extended westward
(8°W) and southward to the Spanish coast.
The spreading and the behaviour of the Adour plume are not wellknown. Sometimes satellite images show relevant evidence of its presence,
especially on temperature (AVHRR) and colour channels (AVHRR, SeaWIFS).
Moreover, survevs (Modycot 98, Pegase 98) have highlighted its shape.
These observations indicate two ttpical situations: the Adour plume is
either spread straight from the estuary or driven northward along the
Landes coast.
Affer a brief description of the numerical model and Modycot 98-3 survey
observations, results of simulation tor the year 1995 will be discussed to
describe the trends and behaviour of the Adour plume during a whole year.
49
hydrodynamic model
Anne-Marie Jégou, Franck Dumas, Pascal Lazure
(1) Ifremer Brest, Del/ao, BP 70, 29280 Plouzané, France
amjegou@ifremer.fr
Abstract
The Adour plume evolution is simulated over 1995 with a 3D hydrodynamic model forced with wind and thermal fluxes provided by a meteorological model (Arpege, Météo-France), the tide and the discharges of
the Loire, ( iironde and Adour rivers.
Résumé
Le comportement et l’évolution saisonnière du panache de l’Adour sont
étudiés au moyen d’un modèle hydrodynamique 3D du golfe de Gascogne. L’évolution du panache durant l’année 1995 est simulée en forçant
le modèle par les vents et flux issus du modèle météorologique Arpege de
Météo-France, la marée et les débits mesurés de la Loire, de la Gironde et
de l’Adour.
Introduction
Hydrology over the continental shelf along the French coast shows highly
\ ariable salinities due to an extended plume largely driven by winds. The
dynamic behaviour of the Loire and the Gironde have already been quite
well-documented and studied (Lazure & Jégou, 1998). At the time, the
computed domain of the model used covered the entire Atlantic shelf
from the French coast to the 200 m isobath and from 44°N to 49°N. In
order to take the Adour plume into account and assess the influence of
mesoscale circulation on the shelf, the model was extended westward
(8°W) and southward to the Spanish coast.
The spreading and the behaviour of the Adour plume are not wellknown. Sometimes satellite images show relevant evidence of its presence,
especially on temperature (AVHRR) and colour channels (AVHRR, SeaWIFS).
Moreover, survevs (Modycot 98, Pegase 98) have highlighted its shape.
These observations indicate two ttpical situations: the Adour plume is
either spread straight from the estuary or driven northward along the
Landes coast.
Affer a brief description of the numerical model and Modycot 98-3 survey
observations, results of simulation tor the year 1995 will be discussed to
describe the trends and behaviour of the Adour plume during a whole year.
49