|
|
|
Registros recuperados: 14.873 | |
|
|
Hauck, Judith; Zeising, Moritz; Le Quere, Corinne; Gruber, Nicolas; Bakker, Dorothee C. E.; Bopp, Laurent; Chau, Thi Tuyet Trang; Guerses, Oezguer; Ilyina, Tatiana; Landschuetzer, Peter; Lenton, Andrew; Resplandy, Laure; Roedenbeck, Christian; Schwinger, Joerg; Seferian, Roland. |
Based on the 2019 assessment of the Global Carbon Project, the ocean took up on average, 2.5 +/- 0.6 PgC yr(-1) or 23 +/- 5% of the total anthropogenic CO2 emissions over the decade 2009-2018. This sink estimate is based on simulation results from global ocean biogeochemicalmodels (GOBMs) and is compared to data-products based on observations of surface ocean pCO(2) (partial pressure of CO2) accounting for the outgassing of river-derived CO2. Here we evaluate the GOBM simulations by comparing the simulated surface ocean pCO(2) to observations. Based on this comparison, the simulations are well-suited for quantifying the global ocean carbon sink on the time-scale of the annual mean and its multi-decadal trend (RMSE <20... |
Tipo: Text |
Palavras-chave: Ocean carbon uptake; Anthropogenic CO2; Ocean carbon cycle model evaluation; Riverine carbon flux; Variability of the ocean carbon sink; Seasonal cycle. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78822/81139.pdf |
| |
|
|
Feucher, Charlene; Maze, Guillaume; Mercier, Herle. |
A global reference state of the subtropical mode waters and permanent pycnoclines properties for the 2000‐2015 period is presented. The climatology is obtained from a pattern recognition algorithm applied to stratification profiles from the Argo global array. The stratification features are identified as permanent upper ocean pycnostad and pycnocline even when the seasonal pycnocline is developed. The climatology shows that both Northern Hemisphere subtropical gyres have a qualitatively very similar stratification structure. The permanent pycnocline in the North Atlantic and North Pacific show two deep centers colocated with thick subtropical and subpolar mode waters. These centers coincide with modes in the density and stratification space. These deep... |
Tipo: Text |
Palavras-chave: Subtropical gyre; Pycnocline; Argo; Global ocean; Stratification. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00480/59176/61817.pdf |
| |
|
|
Rousselet, L.; Doglioli, A.m.; De Verneil, A.; Pietri, A.; Della Penna, A.; Berline, L.; Marrec, P.; Grégori, G.; Thyssen, M.; Carlotti, F.; Barillon, S.; Simon‐bot, F.; Bonal, M.; D'Ovidio, F.; Petrenko, A.. |
Vertical velocities can be estimated indirectly from in situ observations by theoretical frameworks like the ω‐equation. Direct measures of vertical exchanges are challenging due to their typically ephemeral spatiotemporal scales. In this study we address this problem with an adaptive sampling strategy coupling various biophysical instruments. We analyze the 3‐D organization of a cyclonic mesoscale structure finely sampled during the OSCAHR (Observing Submesoscale Coupling At High Resolution) cruise in the Ligurian Sea during fall 2015. The observations, acquired with a Moving Vessel Profiler (MVP), highlight a subsurface low‐salinity layer (≃ 50 m), as well as rising isopycnals, generated by geostrophic cyclonic circulation, in the structure's center.... |
Tipo: Text |
Palavras-chave: High-resolution reconstructions of 3-D fields; Vertical velocities estimated with omega-equation; Particle distribution as a tracer for vertical advection. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00490/60214/63567.pdf |
| |
|
|
Ratie, G.; Quantin, C.; Maia De Freitas, A.; Echevarria, G.; Ponzevera, Emmanuel; Garnier, J.. |
Ultramafic derived soils are characterized by low nutrient soils, a low Ca:Mg ratio, and high metal contents such as Ni, Co and Cr. The vegetation growing on these soils is highly adapted and includes both Ni hyperaccumulator and accumulator species. Today, approximately 530 Ni hyperaccumulator species are listed worldwide and the Ni concentration can be extremely high, e.g. up to 25% in latex from Pycnandra acuminata (Sapotaceae), a tree found in New Caledonia. The aim of this study is to identify the potential role of Ni hyperaccumulator plants in the Ni biogeochemical cycle at the soil surface by using Ni isotopes. A set of Ni hyperaccumulator and Ni accumulator plants as well as topsoils were sampled on the Barro Alto and Niquelândia ultramafic... |
Tipo: Text |
Palavras-chave: Nickel; Isotope; Ni hyperaccumulator species; Ultramafic environment. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00464/57565/59740.pdf |
| |
|
|
Sangare, Nathanael; Lo-yat, Alain; Le Moullac, Gilles; Pecquerie, Laure; Thomas, Yoann; Beliaeff, Benoit; Andrefouet, Serge. |
In French Polynesia black pearl farming represents one of the dominant business sectors. However, it still entirely relies on unpredictable Pinctada margaritifera spat collection success, which is itself conditioned by larval development completion. To assess the relationship between larval development and recruitment success, we studied under controlled conditions the effect of food concentration on development, growth, ingestion rate, survival and metabolic rate at the larval stage. Larvae were exposed to four different phytoplankton densities (2,5; 7,5; 15 and 30 cell.μL−1). Larvae survived equally all over the range of phytoplankton concentration with an average survival rate of 16% at the end of experiments. Food concentration significantly affected... |
Tipo: Text |
Palavras-chave: Bivalve larvae; Pinctada margaritifera; Physiology; Energetics; Dynamic energy budget theory; Pearl farming; Aquaculture. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00476/58795/61446.pdf |
| |
|
|
Artetxe-arrate, Iraide; Fraile, Igaratza; Farley, Jessica; Darnaude, Audrey M.; Clear, Naomi; Rodríguez-ezpeleta, Naiara; Dettman, David L.; Pécheyran, Christophe; Krug, Iñigo; Médieu, Anais; Ahusan, Mohamed; Proctor, Craig; Priatna, Asep; Lestari, Pratiwi; Davies, Campbell; Marsac, Francis; Murua, Hilario. |
The chemical composition of otoliths (earbones) can provide valuable information about stock structure and connectivity patterns among marine fish. For that, chemical signatures must be sufficiently distinct to allow accurate classification of an unknown fish to their area of origin. Here we have examined the suitability of otolith microchemistry as a tool to better understand the spatial dynamics of skipjack tuna (Katsuwonus pelamis), a highly valuable commercial species for which uncertainties remain regarding its stock structure in the Indian Ocean. For this aim, we have compared the early life otolith chemical composition of young-of-the-year (<6 months) skipjack tuna captured from the three main nursery areas of the equatorial Indian Ocean (West,... |
Tipo: Text |
|
Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00687/79908/82810.pdf |
| |
|
|
Kersalé, Marion; Perez, Renellys C.; Speich, Sabrina; Meinen, Christopher S.; Lamont, Tarron; Le Hénaff, Matthieu; Van Den Berg, Marcel A.; Majumder, Sudip; Ansorge, Isabelle J.; Dong, Shenfu; Schmid, Claudia; Terre, Thierry; Garzoli, Silvia L.. |
The first in situ continuous full‐water‐column observations of the Eastern Boundary Currents (EBCs) at 34.5°S in the South Atlantic are obtained using 23 months of data from a line of Current and Pressure recording Inverted Echo Sounders (CPIES) spanning the Cape Basin. The CPIES are used to evaluate the mean structure of the EBC, the associated water masses, and the volume transport variability. The estimated northward time‐mean Benguela Current absolute geostrophic transport is 24 Sv, with a temporal standard deviation of 17 Sv. Beneath this current the time‐mean transport is southward, indicating the presence of a deep‐EBC (DEBC), with a time‐mean transport of 12 Sv, and a standard deviation of 17 Sv. Offshore of these currents, the shallow and deep... |
Tipo: Text |
|
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00479/59022/61644.pdf |
| |
|
|
Bourlès, Bernard; Araujo, Moacyr; Mcphaden, Michael J.; Brandt, Peter; Foltz, Gregory R.; Lumpkin, Rick; Giordani, Hervé; Hernandez, Fabrice; Lefèvre, Nathalie; Nobre, Paulo; Campos, Edmo; Saravanan, Ramalingam; Trotte‐duhà, Janice; Dengler, Marcus; Hahn, Johannes; Hummels, Rebecca; Lübbecke, Joke F.; Rouault, Mathieu; Cotrim, Leticia; Sutton, Adrienne; Jochum, Markus; Perez, Renellys C. |
PIRATA is a multinational program initiated in 1997 in the tropical Atlantic to improve our understanding and ability to predict ocean‐atmosphere variability. PIRATA consists of a network of moored buoys providing meteorological and oceanographic data transmitted in real‐time to address fundamental scientific questions as well as societal needs. The network is maintained through dedicated yearly cruises, which allow for extensive complementary shipboard measurements and provide platforms for deployment of other components of the Tropical Atlantic Observing System. This paper describes network enhancements, scientific accomplishments and successes obtained from the last 10 years of observations, as well as additional results enabled by cooperation with... |
Tipo: Text |
|
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00485/59680/62752.pdf |
| |
|
|
Rimaud, Thomas; Le Barzic, Franck; Mehault, Sonia. |
De nombreuses évolutions technologiques ont été mises en place en 2012, 2015 (Reg UE 737/2012 et Reg UE 2015/741) puis en 2019 et 2020 (Reg UE 2018/2034 et Reg UE 2019/2239) sur les pêcheries chalutières en mer Celtique. Dans le contexte de gestion des gadidés (cabillaud, merlan et églefin), cette étude a comme objectif de quantifier et qualifier les échappements de 3 dispositifs (110mm/PMC120mm, 100mm/PMC160mm, 120mm) par rapport à un chalut standard dont le cul a un maillage de 100mm ; engin utilisé par les chalutiers français en Zone de Protection Mer Celtique avant 2012 et qui est désormais le maillage de référence en Mer Celtique. Chacun des dispositifs a été testé en condition réelles sur différents navires entre... |
Tipo: Text |
|
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00677/78882/81169.pdf |
| |
|
|
Gregor, Luke; Lebehot, Alice D.; Kok, Schalk; Monteiro, Pedro M. Scheel. |
Over the last decade, advanced statistical inference and machine learning have been used to fill the gaps in sparse surface ocean CO2 measurements (Rodenbeck et al., 2015). The estimates from these methods have been used to constrain seasonal, interannual and decadal variability in sea-air CO2 fluxes and the drivers of these changes (Landschutzer et al., 2015, 2016; Gregor et al., 2018). However, it is also becoming clear that these methods are converging towards a common bias and root mean square error (RMSE) boundary: "the wall", which suggests that pCO(2) estimates are now limited by both data gaps and scale-sensitive observations. Here, we analyse this problem by introducing a new gap-filling method, an ensemble... |
Tipo: Text |
|
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00676/78797/81035.pdf |
| |
|
|
Ifremer/ODE/LITTORAL/LERLR/20.06/Laboratoire Environnement Ressources du Languedoc‐Roussillon. |
L’Ifremer coordonne, sur l’ensemble du littoral métropolitain, la mise en œuvre des réseaux d’observation et de surveillance de la mer côtière. Ces outils de collecte de données sur l’état du milieu marin répondent à deux objectifs : · servir des besoins institutionnels en fournissant aux pouvoirs publics des informations répondant aux exigences de la Directive Cadre sur l’Eau (DCE), de la directive Cadre sur la Stratégie Milieu Marin (DCSMM), des conventions de mers régionales (OSPAR et Barcelone) et de la réglementation sanitaire relative à la salubrité des coquillages de production conchylicoles ou de pêche ; · acquérir des séries de données nourrissant les programmes de recherche visant à mieux comprendre le fonctionnement des... |
Tipo: Text |
|
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00643/75464/76287.pdf |
| |
|
|
Yatheesh, V.; Dyment, J.; Bhattacharya, G. C.; Royer, Jean-yves; Raju, K. A. Kamesh; Ramprasad, T.; Chaubey, A. K.; Patriat, P.; Srinivas, K.; Choi, Y.. |
The Central Indian Ocean, namely the Central Indian, Crozet, and Madagascar basins, formed by rifting and subsequent drifting of India (now Capricorn), Antarctica, and Africa (now Somalia). We gathered a comprehensive set of sea surface magnetic anomaly profiles over these basins and revisited location and identification of magnetic isochrons between C34ny (83.0 Ma) and C20ny (42.536 Ma) using the objective analytic signal technique. We present high-resolution magnetic isochrons for 29 periods based on similar to 1,400 magnetic anomaly picks. From the conjugate sets of picks, we derive two-plate finite rotation parameters for both the Capricorn-Antarctica and Capricorn-Somalia motions. These finite rotations are compared to three-plate reconstructions of... |
Tipo: Text |
Palavras-chave: Magnetic isochrons; Central Indian Basin; Crozet Basin; Madagascar Basin; Plate reconstruction. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74935/76014.pdf |
| |
|
|
ICES. |
The ICES Inter-Benchmark Protocol of sole in the Eastern English Channel stock (IBPsol7d) met to investigate the effect of the missing UK beam trawl commercial index (UK-CBT) in 2017 and 2018, that was related to the recent change in the database system in UK. The aim was to inves-tigate the internal consistency of the new UK-CBT and to analyse its influence on the sole in 7d assessment. The model currently used to assess this stock is an extended survival analysis (XSA). No other model was tested. During the IBP, it was decided to revise the Belgium beam trawl commercial index (BE-CBT) to move from a Landing Per Unit of Effort (LPUE) index to a Catch Per Unit of Effort (CPUE). This decision was motivated by the increase... |
Tipo: Text |
|
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00615/72742/71889.pdf |
| |
|
| |
|
|
Dilmahamod, Ahmad Fehmi; Penven, Pierrick; Aguiar gonzalez, B.; Reason, C. J. C.; Hermes, J. C.. |
The South‐East Madagascar Bloom occurs in an oligotrophic region of the South‐West Indian Ocean. Phase‐locked to austral summer, this sporadic feature exhibits substantial temporal and spatial variability. Several studies, with different hypotheses, have focused on the initiation mechanism triggering the bloom but none has been as yet clearly substantiated. With 19‐years of ocean colour dataset available as well as in‐situ measurements (Argo profiles), the time is ripe to review this feature. The bloom is characterized in a novel manner and a new bloom index is suggested, yielding 11 bloom years, including 3 major bloom years (1999, 2006 and 2008). Spatially, the bloom varies from a mean structure (22° S‐32° S; 50° E‐∼70°E) both zonally and meridionally. A... |
Tipo: Text |
Palavras-chave: South-East Madagascar Bloom; South-East Madagascar Current; La Nina; Cyanobacterial bloom. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00482/59338/62118.pdf |
| |
|
|
Bajjouk, Touria; Cordier, Celine; Auby, Isabelle; Liabot, Pierre-olivier; Kerninon, Fanny; Le Bouffant, Naig; Trut, Gilles; Oger-jeanneret, Helene. |
Les phanérogames marines sont devenues ces dernières années des "espèces phares". Habitat à forte valeur écologique et patrimoniale, les herbiers bénéficient de mesures de gestion et de protection à différentes échelles : locale, nationale et internationale. Il y a donc un contexte favorable pour que les connaissances sur les herbiers progressent et que leur dynamique spatio-temporelle soit surveillée à une échelle globale. Depuis quelques années, et en lien avec les exigences des directives européennes, les phanérogames marines ont servi de support pour le développement et la valorisation des outils et techniques de télédétection pour la planification d'une gestion et d’une stratégie de surveillance efficace. En France, les méthodes pour évaluer les... |
Tipo: Text |
|
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00514/62528/66891.pdf |
| |
|
|
Menesguen, Alain; Dussauze, Morgan; Dumas, Franck; Thouvenin, Benedicte; Garnier, Valerie; Lecornu, Fabrice; Repecaud, Michel. |
European directives (Water Framework Directive - WFD and Marine Strategy Framework Directive - MSFD) require a regular survey of several descriptors of the Environmental Status of coastal waters of the North-east Atlantic Ocean. Especially for the MSFD, which may concern large continental shelf areas where measurements are scarce, realistic ecological models can help assessing the Environmental Status. The ECO-MARS3D model of the pelagic ecosystem of the Bay of Biscay and English Channel continental shelf (NE Atlantic) has been developed for these applied purposes and validated against various types of historic data. This first paper deals with the basic biogeochemical version, which contains inorganic nutrients (NH4, NO3, PO4, Si(OH)4), three... |
Tipo: Text |
Palavras-chave: Ecological 3D model; Continental shelf; Bay of Biscay and English Channel; Surface chlorophyll; Dissolved oxygen; MSFD. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00469/58098/60510.pdf |
| |
|
|
Mtshali, T.n.; Horsten, N.r.; Thomalla, S.j.; Ryan‐keogh, T.j.; Nicholson, S.‐a.; Roychoudhury, A.n.; Bucciarelli, Eva; Sarthou, Geraldine; Tagliabue, A.; Monteiro, P.m.s.. |
Seasonal progression of dissolved iron (DFe) concentrations in the upper water column were examined during four occupations in the Atlantic sector of the Southern Ocean. DFe inventories from euphotic and aphotic reservoirs decreased progressively from July to February, while dissolved inorganic nitrogen (DIN) decreased from July to January with no significant change between January and February. Results suggest that between July and January, DFe loss from both euphotic and aphotic reservoirs were predominantly in support of phytoplankton growth (Iron to carbon (Fe:C) uptake ratio of 16±3 μmol mol‐1) highlighting the importance of the “winter DFe‐reservoir” for biological uptake. During January to February, excess loss of DFe relative to DIN (Fe:C uptake... |
Tipo: Text |
|
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00487/59914/63095.pdf |
| |
|
|
Tang, Weiyi; Li, Zuchuan; Cassar, Nicolas. |
Marine nitrogen (N2) fixation supplies “new” nitrogen to the global ocean, supporting uptake and sequestration of carbon. Despite its central role, marine N2 fixation and its controlling factors remain elusive. In this study, we compile over 1,100 published observations to identify the dominant predictors of marine N2 fixation and derive global estimates based on the machine learning algorithms of random forest (RF) and support vector regression (SVR). We find that no single environmental property predicts N2 fixation at global scales. Our RF and SVR algorithms, trained with sampling coordinates and month, solar radiation, wind speed, sea surface temperature, sea surface salinity, surface nitrate, surface phosphate, surface excess phosphorus, minimum... |
Tipo: Text |
Palavras-chave: N-2 fixation; Machine-learning; Ocean. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00483/59501/62371.pdf |
| |
|
|
Castrec, Justine; Hegaret, Helene; Alunno-bruscia, Marianne; Picard, Mailys; Soudant, Philippe; Petton, Bruno; Boulais, Myrina; Suquet, Marc; Queau, Isabelle; Ratiskol, Dominique; Foulon, Valentin; Le Goic, Nelly; Fabioux, Caroline. |
Harmful algal blooms are a threat to aquatic organisms and coastal ecosystems. Among harmful species, the widespread distributed genus Alexandrium is of global importance. This genus is well-known for the synthesis of paralytic shellfish toxins which are toxic for humans through the consumption of contaminated shellfish. While the effects of Alexandrium species upon the physiology of bivalves are now well documented, consequences on reproduction remain poorly studied. In France, Alexandrium minutum blooms have been recurrent for the last decades, generally appearing during the reproduction season of most bivalves including the oyster Crassostrea gigas. These blooms could not only affect gametogenesis but also spawning, larval development or juvenile... |
Tipo: Text |
Palavras-chave: Harmful algal bloom (HAB); Paralytic shellfish toxin (PST); Crassostrea gigas; Gametes; Larvae. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00469/58099/60512.pdf |
| |
Registros recuperados: 14.873 | |
|
|
|