|
|
|
| Registros recuperados: 36 | |
|
|
| Martinez, Elodie; Raapoto, Hirohiti; Maes, Christophe; Maamaatuaihutapu, Keitapu. |
| The Marquesas form an isolated group of small islands in the Central South Pacific where quasi-permanent biological activity is observed. During La Niña events, this biological activity, shown by a net increase of chlorophyll-a concentration (Chl, a proxy of phytoplankton biomass), is particularly strong. It has been hypothesized that this strong activity is due to iron-rich waters advected from the equatorial region to the Marquesas by tropical instability waves (TIWs). Here we investigate this hypothesis over 18 years by combining satellite observations, re-analyses of ocean data, and Lagrangian diagnostics. Four La Niña events ranging from moderate to strong intensity occurred during this period, and our results show that the Chl plume within the... |
| Tipo: Text |
Palavras-chave: Tropical instability waves; La Nina; Chlorophyll-a concentration variability; Ocean colour; Island mass effect; Marquesas islands; Oceanography; Satellite observations. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00437/54858/56346.pdf |
| |
|
|
| De Verneil, Alain; Rousselet, Louise; Doglioli, Andrea M.; Petrenko, Anne A.; Maes, Christophe; Bouruet-aubertot, Pascale; Moutin, Thierry. |
| Research cruises to quantify biogeochemical fluxes in the ocean require taking measurements at stations lasting at least several days. A popular experimental design is the quasi-Lagrangian drifter, with in situ incubations that follow the flow of water over time. The ship then tracks the drifter because subsequent measurements are supposed to remain in the same water environment. An outstanding question is how to best determine whether this is true. During the Oligotrophy to UlTra-oligotrophy PACific Experiment (OUTPACE) cruise, from 18 February to 3 April 2015 in the western tropical South Pacific, three separate stations of long duration (five days) over the upper 500 m were conducted in this quasi-Lagrangian sampling scheme. Here we present physical... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00420/53122/54075.pdf |
| |
|
| |
|
|
| Reul, Nicolas; Grodsky, S.a.; Arias, M.; Boutin, J.; Catany, R.; Chapron, Bertrand; D'Amico, F; Dinnat, E.; Donlon, C.; Fore, A.; Fournier, Severine; Guimbard, Sebastien; Hasson, A.; Kolodziejczyk, Nicolas; Lagerloef, G.; Lee, T.; Le Vine, D.m.; Lindstrom, E.; Maes, Christophe; Mecklenburg, S.; Meissner, T.; Olmedo, E.; Sabia, R.; Tenerelli, Joseph; Thouvenin-masson, C.; Turiel, A.; Vergely, J.l.; Vinogradova, N.; Wentz, F.; Yueh, S.. |
| Operated since the end of 2009, the European Space Agency (ESA) Soil Moisture and Ocean Salinity (SMOS) satellite mission is the first orbiting radiometer that collects regular and global observations from space of two Essential Climate Variables of the Global Climate Observing System: Sea Surface Salinity (SSS) and Soil Moisture. The National Aeronautics and Space Administration (NASA) Aquarius mission, with the primary objective to provide global SSS measurements from space operated from mid-2011 to mid-2015. NASA's Soil Moisture Active-Passive (SMAP) mission, primarily dedicated to soil moisture measurements, but also monitoring SSS, has been operating since early 2015. The primary sensors onboard these three missions are passive microwave radiometers... |
| Tipo: Text |
Palavras-chave: Sea surface salinity; Ocean microwave remote sensing; Radiometer; L-band; SMOS; Aquarius/SAC-D; SMAP. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00615/72750/71894.pdf |
| |
|
|
| Rousselet, Louise; De Verneil, Alain; Doglioli, Andrea M.; Petrenko, Anne A.; Duhamel, Solange; Maes, Christophe; Blanke, Bruno. |
| The patterns of the large-scale, meso- and submesoscale surface circulation on biogeochemical and biological distributions are examined in the Western Tropical South Pacific (WTSP) in the context of the OUTPACE cruise (Feb–April 2015). Multi-disciplinary original in situ observations were achieved along a zonal transect through the WTSP and their analysis was coupled with satellite data. The use of Lagrangian diagnostics allows for the identification of water mass pathways, mesoscale structures, and submesoscale features such as fronts. In particular, we confirmed the existence of a global wind-driven southward circulation of surface waters in the entire WTSP, using a new high-resolution altimetry-derived product, validated by in situ drifters, that... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00420/53119/54071.pdf |
| |
|
|
| Alory, Gael; Maes, Christophe; Delcroix, Thierry; Reul, Nicolas; Illig, Serena. |
| The freshest surface waters in the tropical Pacific are found at its eastern boundary. Using in situ observations, we depict the quasi-permanent presence of a far eastern Pacific fresh pool with Sea Surface Salinity (SSS) lower than 33, which is confined between Panama's west coast and 85W in December and extends westward to 95W in April. Strong SSS fronts are found at the outer edge of this fresh pool. We investigate the seasonal dynamics of the fresh pool using complementary satellite wind, rain, sea level and in situ oceanic current data at the surface, along with hydrographic profiles. The fresh pool appears off Panama due to the strong summer rains associated with the northward migration of the ITCZ over Central America in June. During the second half... |
| Tipo: Text |
|
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00072/18311/16581.pdf |
| |
|
|
| Ardhuin, Fabrice; Brandt, Peter; Gaultier, Lucile; Donlon, Craig; Battaglia, Alessandro; Boy, François; Casal, Tania; Chapron, Bertrand; Collard, Fabrice; Cravatte, Sophie; Delouis, Jean Marc; De Witte, Erik; Dibarboure, Gerald; Engen, Geir; Johnsen, Harald; Lique, Camille; Lopez-dekker, Paco; Maes, Christophe; Martin, Adrien; Marié, Louis; Menemenlis, Dimitris; Nouguier, Frederic; Peureux, Charles; Rampal, Pierre; Ressler, Gerhard; Rio, Marie-helene; Rommen, Bjorn; Shutler, Jamie D.; Suess, Martin; Tsamados, Michel; Ubelmann, Clement; Van Sebille, Erik; Van Den Oever, Martin; Stammer, Detlef. |
| The Sea surface KInematics Multiscale monitoring (SKIM) satellite mission is designed to explore ocean surface current and waves. This includes tropical currents, notably the poorly known patterns of divergence and their impact on the ocean heat budget, and monitoring of the emerging Arctic up to 82.5°N. SKIM will also make unprecedented direct measurements of strong currents, from boundary currents to the Antarctic circumpolar current, and their interaction with ocean waves with expected impacts on air-sea fluxes and extreme waves. For the first time, SKIM will directly measure the ocean surface current vector from space. The main instrument on SKIM is a Ka-band conically scanning, multi-beam Doppler radar altimeter/wave scatterometer that includes a... |
| Tipo: Text |
Palavras-chave: Ocean current; Tropics; Arctic; Doppler; Altimetry; Sea state; Remote sensing; Ocean waves. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00498/60964/64372.pdf |
| |
|
|
| Sauzède, Raphaëlle; Martinez, Elodie; Pasqueron De Fommervault, Orens; Poteau, Antoine; Mignot, Alexandre; Maes, Christophe; Claustre, Hervé; Uitz, Julia; Maamaatuaiahutapu, Keitapu; Rodier, Martine; Schmechtig, Catherine; Laurent, Victoire. |
| The South Pacific Subtropical Gyre (SPSG) is a vast and remote area where large uncertainties on variability in phytoplankton biomass and production remain due to the lack of biogeochemical in situ observations. In such oligotrophic environments, ecosystems are predominantly controlled by nutrients depletion in surface waters. However, this oligotrophic character can be disturbed in the vicinity of islands where enhancement of biological activity is known to occur (i.e. the island mass effect, IME). This study mainly focuses on in situ observations showing that an IME can be evidenced leeward of Tahiti (17.7° S–149.5° W), French Polynesia. Concomitant physical and biogeochemical observations collected with two Biogeochemical-Argo (BGC-Argo) profiling... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00421/53295/54108.pdf |
| |
|
| |
|
| |
|
|
| Bourras, Denis; Cambra, Remi; Marié, Louis; Bouin, Marie-noëlle; Baggio, Lucio; Branger, Hubert; Beghoura, Houda; Reverdin, Gilles; Dewitte, Boris; Paulmier, Aurélien; Maes, Christophe; Ardhuin, Fabrice; Pairaud, Ivane; Fraunié, Philippe; Luneau, Christopher; Hauser, Danièle. |
| Turbulent fluxes at the air‐sea interface are estimated with data collected in 2011 to 2017 with a low‐profile platform during six experiments in four regions. The observations were carried out with moderate winds (2‐10 m s‐1) and averaged wave heights of 1.5 m. Most of the time, there was a swell, with an averaged wave age (the ratio between wave phase speed and wind speed) being equal to 2.8±1.6. Three flux calculation methods are used, namely the eddy‐covariance (EC), the inertial‐dissipation (ID), and the bulk methods. For the EC method, a spectral technique is proposed to correct wind data from platform motion. A mean bias affecting the friction velocity (u*) is then evaluated. The comparison between EC u* and ID u* estimates suggests that a constant... |
| Tipo: Text |
|
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00503/61436/65156.pdf |
| |
|
|
| Barbot, Simon; Petrenko, Anne; Maes, Christophe. |
| Thanks to the autonomous Argo floats of the OUTPACE cruise (Oligotrophy to UlTra-oligotrophy PACific Experiment) and of the THOT (TaHitian Ocean Time series) project, some features of intermediate-flow dynamics, at around 1000 m depth, within the central and western South Pacific Ocean (around 19° S, 156° E–150° W) are described. In the Coral Sea, we highlight minima in dissolved oxygen of 140 µmol kg−1 that are associated with the signature of a southward transport of waters between two zonal jets: from the North Vanuatu Jet to the North Caledonia Jet. This transport takes place in the core of a cyclonic eddy or via the path between a cyclonic eddy and an anticyclonic one, highlighting the importance of mesoscale dynamics in upper thermocline and surface... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00448/56005/57512.pdf |
| |
|
|
| 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 |
| |
|
|
| 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 |
| |
|
| |
|
|
| Dobler, Delphine; Huck, Thierry; Maes, Christophe; Grima, Nicolas; Blanke, Bruno; Martinez, Elodie; Ardhuin, Fabrice. |
| In the open ocean, floating surface debris such as plastics concentrate in five main accumulation zones centered around 30° latitude, far from highly turbulent areas. Using Lagrangian advection of numerical particles by surface currents from ocean model reanalysis, previous studies have shown long-distance connection from the accumulation zones of the South Indian to the South Pacific oceans. An important physical process affecting surface particles but missing in such analyses is wave-induced Stokes drift. Taking into account surface Stokes drift from a wave model reanalysis radically changes the fate of South Indian particles. The convergence region moves from the east to the west of the basin, so particles leak to the South Atlantic rather than the... |
| Tipo: Text |
Palavras-chave: Marine debris; Microplastics; Stokes drift; Indian Ocean; Lagrangian analysis; Ocean surface pathways. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00512/62320/69273.pdf |
| |
|
|
| Bretagnon, Marine; Paulmier, Aurelien; Garcon, Veronique; Dewitte, Boris; Illig, Serena; Leblond, Nathalie; Coppola, Laurent; Campos, Fernando; Velazco, Federico; Panagiotopoulos, Christos; Oschlies, Andreas; Martin Hernandez-ayon, J.; Maske, Helmut; Vergara, Oscar; Montes, Ivonne; Martinez, Philippe; Carrasco, Edgardo; Grelet, Jacques; Desprez-de-gesincourt, Olivier; Maes, Christophe; Scouarnec, Lionel. |
| The fate of the organic matter (OM) produced by marine life controls the major biogeochemical cycles of the Earth's system. The OM produced through photosynthesis is either preserved, exported towards sediments or degraded through remineralisation in the water column. The productive eastern boundary upwelling systems (EBUSs) associated with oxygen minimum zones (OMZs) would be expected to foster OM preservation due to low O-2 conditions. But their intense and diverse microbial activity should enhance OM degradation. To investigate this contradiction, sediment traps were deployed near the oxycline and in the OMZ core on an instrumented moored line off Peru. Data provided high-temporal-resolution O-2 series characterising two seasonal steady states at the... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00486/59764/62889.pdf |
| |
|
|
| Raapoto, Hirohiti; Martinez, Elodie; Petrenko, Anne; Doglioli, Andrea; Gorgues, Thomas; Sauzède, Raphaëlle; Maamaatuaiahutapu, Keitapu; Maes, Christophe; Menkes, Christophe; Lefèvre, Jérôme. |
| A remarkable chlorophyll‐a concentration (Chl, a proxy of phytoplankton biomass) plume can be noticed on remotely sensed ocean color observations at the boundary separating the equatorial mesotrophic from the subtropical oligotrophic waters in the central South Pacific Ocean. This prominent biological feature is known as the island mass effect of the Marquesas archipelago. Waters surrounding these islands present high macronutrient concentrations but an iron depletion. In this study, the origin of Chl enhancement is investigated using a modeling approach. Four simulations based on identical physical and biogeochemical forcings but with different iron sources are conducted and analyzed. Only simulations considering an iron input from the island sediments... |
| Tipo: Text |
|
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00592/70397/68481.pdf |
| |
|
| |
|
|
| Hernandez-ayon, Jose M.; Paulmier, Aurélien; Garcon, Veronique; Sudre, Joel; Montes, Ivonne; Chapa-balcorta, Cecilia; Durante, Giovanni; Dewitte, Boris; Maes, Christophe; Bretagnon, Marine. |
| The oxygen minimum zone (OMZ) of Peru is recognized as a source of CO2 to the atmosphere due to upwelling that brings water with high concentrations of dissolved inorganic carbon (DIC) to the surface. However, the influence of OMZ dynamics on the carbonate system remains poorly understood given a lack of direct observations. This study examines the influence of a coastal Eastern South Pacific OMZ on carbonate system dynamics based on a multidisciplinary cruise that took place in 2014. During the cruise, onboard DIC and pH measurements were used to estimate pCO2 and to calculate the calcium carbonate saturation state (Ω aragonite and calcite). South of Chimbote (9°S), water stratification decreased and both the oxycline and carbocline moved from 150 m depth... |
| Tipo: Text |
Palavras-chave: OMZ; DIC; PH; Omega aragonite; Upwelling Peruvian system. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70004/67919.pdf |
| |
| Registros recuperados: 36 | |
|
|
|
