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| Ganachaud, Alexandre; Gourdeau, Lionel; Kessler, William. |
| The South Equatorial Current (SEC), the westward branch of the South Pacific subtropical gyre, extends from the equator to 30 degrees S at depth. Linear ocean dynamics predict that the SEC forms boundary currents on the eastern coasts of the South Pacific islands it encounters. Those currents would then detach at the northern and southern tips of the islands, and cross the Coral Sea in the form of jets. The Fiji Islands, the Vanuatu archipelago, and New Caledonia are the major topographic obstacles on the SEC pathway to the Australian coast. Large-scale numerical studies, as well as climatologies, suggest the formation of three jets in their lee: the north Vanuatu jet (NVJ), the north Caledonian jet (NCJ), and the south Caledonian jet (SCJ), implying a... |
| Tipo: Text |
Palavras-chave: Tropical Pacific ocean; Depth integrated flow; Zonal jets; Coral sea; Circulation; Waters; Variability; Generation; Island; Heat. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00207/31809/30221.pdf |
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| Ganachaud, Alexandre; Wunsch, C; Marotzke, J; Toole, J. |
| The large scale Indian Ocean circulation is estimated from a global hydrographic inverse geostrophic box model with a focus on the meridional overturning circulation (MOC), The global model is based an selected recent World Ocean Circulation Experiment (WOCE) sections which in the Indian Basin consist of zonal sections at 32 degreesS, 20 degreesS and 8 degreesS, and a section between Bah and Australia from the Java-Australia Dynamic Experiment (JADE). The circulation is required to conserve mass, salinity, heat, silica and "PO" (170PO(4)+O-2). Near-conservation is imposed within layers bounded by neutral surfaces, while permitting advective and diffusive exchanges between the layers. Conceptually, the derived circulation is an estimate of the average... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00000/10427/9421.pdf |
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| Ganachaud, Alexandre; Mercier, Herle. |
| [1] Wind friction at the ocean surface introduces energetic variations in the net mass transport across the oceanic basins. To conserve mass, the whole water column adjusts rapidly, introducing a depth-independent perturbation in the pressure field. This signal is analyzed in a high resolution numerical model of the Atlantic Ocean. While the pressure perturbation cannot be extracted from the energetic sea surface height signals, it represents up to 90% of the bottom pressure signal when integrated across the Atlantic Ocean in the daily and monthly frequencies. This signal will be an important part of the signal measured by the GRACE (Gravity Recovery And Climate Experiment) mission. |
| Tipo: Text |
Palavras-chave: Eckman transport; Numerical model; Pressure perturbation; Ocean surface. |
| Ano: 2002 |
URL: http://archimer.ifremer.fr/doc/2002/publication-490.pdf |
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| Gasparin, Florent; Ganachaud, Alexandre; Maes, Christophe; Marin, Frederic; Eldin, Gerard. |
| Thermocline waters of the tropical southwest Pacific can be traced back to the center of the South Pacific basin and have a potential influence on equatorial surface conditions and on the characteristics of the El Nino Southern Oscillation on decadal timescales. The Solomon Sea is traversed by this influential flow, and therefore is an optimal place for exploring this oceanic connection to the equator. From a high-resolution hydrographic survey at which we applied an inverse box model, we describe the main pathways at the entrance of the Solomon Sea, and more particularly the extremely sharp bend of the western boundary current around the south-east tip of Papua New Guinea. Of the 30 Sv subtropical waters transported into the Coral Sea from the east, above... |
| Tipo: Text |
Palavras-chave: Coral Sea; Solomon Sea; Oceanic transport. |
| Ano: 2012 |
URL: https://archimer.ifremer.fr/doc/00214/32501/30985.pdf |
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| Ganachaud, Alexandre; Cravatte, Sophie; Sprintall, Janet; Germineaud, Cyril; Alberty, Marion; Jeandel, Catherine; Eldin, Gerard; Metzl, Nicolas; Bonnet, Sophie; Benavides, Mar; Heimburger, Lars-eric; Lefevre, Jerome; Michael, Susanna; Resing, Joseph; Queroue, Fabien; Sarthou, Geraldine; Rodier, Martine; Berthelot, Hugo; Baurand, Francois; Grelet, Jacques; Hasegawa, Takuya; Kessler, William; Kilepak, Moyep; Lacan, Francois; Privat, Emilien; Send, Uwe; Van Beek, Pieter; Souhaut, Marc; Sonke, Jeroen E.. |
| The semi-enclosed Solomon Sea in the southwestern tropical Pacific is on the pathway of a major oceanic circuit connecting the subtropics to the equator via energetic western boundary currents. Waters transiting through this area replenish the Pacific Warm Pool and ultimately feed the equatorial current system, in particular the equatorial undercurrent. In addition to dynamical transformations, water masses undergo nutrient and micronutrient enrichment when coming in contact with the coasts, impacting the productivity of the downstream equatorial region. Broadscale observing systems are not well suited for describing the fine-scale currents and water masses properties in the Solomon Sea, leaving it relatively unexplored. Two multidisciplinary oceanographic... |
| Tipo: Text |
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| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00390/50185/50808.pdf |
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| Gasparin, Florent; Maes, Christophe; Sudre, Joel; Garcon, Veronique; Ganachaud, Alexandre. |
| A water mass analysis of the Coral Sea thermocline waters provides a description of their distribution, pathways and mixture based on recent oceanographic cruises in this region of strong western boundary currents. The Optimum Multiparameter method is used to determine the relative contribution of core water masses based on their measured temperature, salinity and dissolved oxygen. The thermocline waters, carried by the broad South Equatorial Current (SEC), are essentially composed of four core water masses of different origins. Coming from the south, the South Pacic Tropical Water South (SPTWS, σ=25.3 kg.m−3) and the Western South Pa-cic Central Water (WSPCW, σ=26.3 kg.m−3) enter the Coral Sea by the channel between the island of New Caledonia and the... |
| Tipo: Text |
Palavras-chave: Thermocline water masses; Optimal Multiparameter analysis; Southwest Pacific Ocean; Western boundary current. |
| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00220/33147/31619.pdf |
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