The importance of the main external driving
agents in the bay of Biscay hydrographic
changes
Julio Gil, Ricardo Sánchez
Instituto Espanol de Oceanografía, Apdo 240, 39080 Santander, Espana
julio.gil@st.ieo.es
Abstract
The shelf regions around the bay of Biscay (North Iberian Peninsula)
show a well-detined pattern of typical hydrographic situations, achieved
after the combined effects of the main external agents (Poleward Current,
vdnd drag, freshwater run-off and tides). Most appear seasonally, but
their magnitude, time span and synoptic occurrence form a matrix ot
possibilities that result in a particular situation.
Résumé
Les régions du plateau continental du golfe de Gascogne (nord de la
péninsule Ibérique) montrent un modèle bien défini de situations hydrographiques produites par les effets combinés des principaux agents
extérieurs (Poleward Current, la force du vent, les apports d’eau douce et
les marées). La plupart apparaissent saisonnièrement, mais leur magnitude, durée et présence synoptique forment un ensemble de possibilités
créant une situation particulière dans cette région.
Introduction
ln the bay of Biscay shelf regions a particular scenario is annually
achieved, after the combined effects of the main external driving agents,
namely the Poleward Current (PC), wind drag and freshwater run-off,
over which tidal forces impose. Although most of these appear with a
seasonal cadence, both magnitudes, time spans and synoptic occurrence
overwhich they manifest may combine on a matrix of possibilities that
tinally result in a particular situation. In this paper a review of the main
external agents that plat’ a role on the bay of Biscay shelf circulation is
oudined, illustrated with a number of examples over the last decade.
Material and methods
The results presented here were obtained from different suiveys (1995,
July 1998 and 1999, autumn 1996 and 1999, and SESI'Ts 1997 and 1998
cruises). Standard objective analysis techniques were applied.
43
agents in the bay of Biscay hydrographic
changes
Julio Gil, Ricardo Sánchez
Instituto Espanol de Oceanografía, Apdo 240, 39080 Santander, Espana
julio.gil@st.ieo.es
Abstract
The shelf regions around the bay of Biscay (North Iberian Peninsula)
show a well-detined pattern of typical hydrographic situations, achieved
after the combined effects of the main external agents (Poleward Current,
vdnd drag, freshwater run-off and tides). Most appear seasonally, but
their magnitude, time span and synoptic occurrence form a matrix ot
possibilities that result in a particular situation.
Résumé
Les régions du plateau continental du golfe de Gascogne (nord de la
péninsule Ibérique) montrent un modèle bien défini de situations hydrographiques produites par les effets combinés des principaux agents
extérieurs (Poleward Current, la force du vent, les apports d’eau douce et
les marées). La plupart apparaissent saisonnièrement, mais leur magnitude, durée et présence synoptique forment un ensemble de possibilités
créant une situation particulière dans cette région.
Introduction
ln the bay of Biscay shelf regions a particular scenario is annually
achieved, after the combined effects of the main external driving agents,
namely the Poleward Current (PC), wind drag and freshwater run-off,
over which tidal forces impose. Although most of these appear with a
seasonal cadence, both magnitudes, time spans and synoptic occurrence
overwhich they manifest may combine on a matrix of possibilities that
tinally result in a particular situation. In this paper a review of the main
external agents that plat’ a role on the bay of Biscay shelf circulation is
oudined, illustrated with a number of examples over the last decade.
Material and methods
The results presented here were obtained from different suiveys (1995,
July 1998 and 1999, autumn 1996 and 1999, and SESI'Ts 1997 and 1998
cruises). Standard objective analysis techniques were applied.
43