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4. Identifying community assembling zones and connectivity pathways in the Tropical Southwestern Atlantic Ocean

Author

Giachini Tosetto, Everton, Lett, Christophe, Koch‐larrouy, Ariane, Costa Da Silva, Alex, Neumann‐leitão, Sigrid, Nogueira Junior, Miodeli, Barrier, Nicolas, Dossa, Alina Nathanael, Tchilibou, Michel, Bauchot, Perrine, Morvan, Guillaume, Bertrand, Arnaud, Giachini Tosetto, Everton, Lett, Christophe, Koch‐larrouy, Ariane, Costa Da Silva, Alex, Neumann‐leitão, Sigrid, Nogueira Junior, Miodeli, Barrier, Nicolas, Dossa, Alina Nathanael, Tchilibou, Michel, Bauchot, Perrine, Morvan, Guillaume, and Bertrand, Arnaud

Abstract

Dispersal is more intense in the ocean than on land because most marine taxa present planktonic life stages that are transported by currents even without specific morphological traits. Thus, species dispersal shapes the distribution of biodiversity along seascapes and drives the composition of biodiversity assemblages. To identify marine assembling zones which characterise spatial areas particularly prone to receive and retain similar animal assemblages from the regional pool of species through passive dispersal, we propose a community‐based approach grounded on Lagrangian simulations of plankton dispersal. This novel approach was applied to communities (coast, outer shelf, slope, seamounts and islands; 0–80 m depth) of the Tropical Southwestern Atlantic and used to assess connectivity pathways. For that, we classified the modelled particles in 15 categories according to biological traits (planktonic life duration and spawning habitat) of representative planktonic communities. From the hierarchical clustering of the multivariate matrix containing the amount of arriving particles from each category in each cell we defined 14 assembling zones. Results highlighted that the assembling zones were mostly shaped by the degree of exposure to currents and the presence of mesoscale features (eddies, recirculation) derived from the interaction between these currents and coastlines. The boundaries, dispersal and connectivity patterns of these zones consistently align with local and regional in situ spatial distribution and abundance patterns of organisms, and provide an appropriate basis for the formulation of ecological hypotheses in the metacommunity framework to be tested in situ, such as the balance between species sorting and mass effect assembling archetypes. This approach, when coupled with the knowledge of other processes shaping communities' structure and distribution, provides important insights for regions and animal groups for which knowledge is limited or absent, a

Published
2024
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5. Identifying community assembling zones and connectivity pathways in the Tropical Southwestern Atlantic Ocean

Author

Giachini Tosetto, Everton, primary, Lett, Christophe, additional, Koch‐Larrouy, Ariane, additional, Costa da Silva, Alex, additional, Neumann‐Leitão, Sigrid, additional, Nogueira Junior, Miodeli, additional, Barrier, Nicolas, additional, Dossa, Alina Nathanael, additional, Tchilibou, Michel, additional, Bauchot, Perrine, additional, Morvan, Guillaume, additional, and Bertrand, Arnaud, additional

Published
2023
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8. Internal tides off the Amazon shelf – Part 1: The importance of the structuring of ocean temperature during two contrasted seasons.

Author

Assene, Fernand, Koch-Larrouy, Ariane, Dadou, Isabelle, Tchilibou, Michel, Morvan, Guillaume, Chanut, Jérôme, Costa da Silva, Alex, Vantrepotte, Vincent, Allain, Damien, and Tran, Trung-Kien

Subjects
OCEAN temperature, LYOTROPIC liquid crystals, MIXING height (Atmospheric chemistry), HEAT equation, HEAT flux, OCEANIC mixing
Abstract

The impact of internal and barotropic tides on the vertical and horizontal temperature structure off the Amazon River was investigated during two highly contrasted seasons (AMJ: April–May–June; ASO: August–September–October) over a 3-year period from 2013 to 2015. Twin regional simulations, with and without tides, were used to highlight the general effect of tides. The findings reveal that tides have a cooling effect on the ocean from the surface (∼ 0.3 ∘ C) to above the thermocline (∼ 1.2 ∘ C), while warming it up below the thermocline (∼ 1.2 ∘ C). The heat budget analysis indicates that the vertical mixing is the dominant process driving temperature variations within the mixed layer, while it is associated with both horizontal and vertical advection to explain temperature variations below. The increased mixing in the simulations including tides is attributed to breaking of internal tides (ITs) on their generation sites over the shelf break and offshore along their propagation pathways. Over the shelf, mixing is driven by the dissipation of the barotropic tides. In addition, the vertical terms of the heat budget equation exhibit wavelength patterns typical of mode-1 IT. The study highlights the key role of tides and particularly how IT-related vertical mixing shapes the ocean temperature off the Amazon. Furthermore, we found that tides impact the interactions between the upper ocean interface and the overlying atmosphere. They contribute significantly to increasing the net heat flux between the atmosphere and the ocean, with a notable seasonal variation from 33.2 % in AMJ to 7.4 % in ASO seasons. This emphasizes the critical role of tidal dynamics in understanding regional-scale climate. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Internal tides off the Amazon shelf Part I : importance for the structuring of ocean temperature during two contrasted seasons

Author

Assene, Fernand, Koch-larrouy, Ariane, Dadou, Isabelle, Tchilibou, Michel, Morvan, Guillaume, Chanut, Jérôme, Vantrepotte, Vincent, Allain, Damien, Tran, Trung-kien, Assene, Fernand, Koch-larrouy, Ariane, Dadou, Isabelle, Tchilibou, Michel, Morvan, Guillaume, Chanut, Jérôme, Vantrepotte, Vincent, Allain, Damien, and Tran, Trung-kien

Abstract

Tides and internal tides (IT) in the ocean can significantly affect local to regional ocean temperature, including sea surface temperature (SST), via physical processes such as diffusion (vertical mixing) and advection (vertical and horizontal) of water masses. Offshore of the Amazon River, strong IT have been detected by satellite observations and well modelled ; however, their impact on temperature, SST and the identification of the associated processes have not been studied so far. In this work, we use high resolution (1/36°) numerical simulations with and without the tides from an ocean circulation model (NEMO). This model explicitly resolves the internal tides (IT) and is therefore suitable to assess how they can affect ocean temperature in the studied area. We distinguish the analysis for two contrasted seasons, from April to June (AMJ) and from August to October (ASO), since the seasonal stratification off the Amazon River modulates the IT’s response and their influence in temperature. The generation and the propagation of the IT in the model are in good agreement with observations. The SST reproduced by the simulation including tides is in better agreement with satellite SST data compared to the simulation without tides. During ASO season, stronger meso-scale currents, deeper and weaker pycnocline are observed in contrast to the AMJ season. The observed coastal upwelling during ASO season is better reproduced by the model including tides, whereas the no-tide simulation is too warm by +0.3 °C for the SST. In the subsurface above the thermocline, the tide simulation is cooler by −1.2 °C, and warmer below the thermocline by +1.2 °C compared to the simulation without the tides. The IT induce vertical mixing on their generation site along the shelf break and on their propagation pathways towards the open ocean. This process mainly explains the cooler temperature at the ocean surface and is combined with vertical and horizontal advection to explain the cooling in

Published
2023
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14. A NEMO-based model of <i>Sargassum</i> distribution in the tropical Atlantic: description of the model and sensitivity analysis (NEMO-Sarg1.0)

Author

Jouanno, Julien, primary, Benshila, Rachid, additional, Berline, Léo, additional, Soulié, Antonin, additional, Radenac, Marie-Hélène, additional, Morvan, Guillaume, additional, Diaz, Frédéric, additional, Sheinbaum, Julio, additional, Chevalier, Cristele, additional, Thibaut, Thierry, additional, Changeux, Thomas, additional, Menard, Frédéric, additional, Berthet, Sarah, additional, Aumont, Olivier, additional, Ethé, Christian, additional, Nabat, Pierre, additional, and Mallet, Marc, additional

Published
2021
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16. A NEMO-based model of Sargassum distribution in the Tropical Atlantic 

Author

Benshila, Rachid, primary, Jouanno, Julien, additional, Berline, Léo, additional, Soulié, Antonin, additional, Marie-Hélène, Marie-Hélène, additional, Morvan, Guillaume, additional, Diaz, Frédéric, additional, Sheinbaum, Julio, additional, Chevalier, Cristele, additional, Thibaut, Thierry, additional, Changeux, Thomas, additional, Menard, Frédéric, additional, Berthet, Sarah, additional, Aumont, Olivier, additional, Ethé, Christian, additional, Nabat, Pierre, additional, and Mallet, Marc, additional

Published
2021
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17. Metabolic fingerprint of Chardonnay leaves affected by esca disease is clone and year dependent

Author

Moret, Florian, Clément, Gilles, Grosjean, Claire, Lemaitre Guillier, Christelle, Morvan, Guillaume, Trouvelot, Sophie, Adrian, Marielle, Fontaine, Florence, Agroécologie [Dijon], Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut Jean-Pierre Bourgin (IJPB), AgroParisTech-Université Paris-Saclay-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Chambre Régionale d’Agriculture de Bourgogne Franche-Comté (CRA BFC), Chambre d’Agriculture de l’Yonne, 14 Bis Rue Guynemer, 89000 Auxerre, France, SFR Condorcet, Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS), Bureau Interprofessionnel des Vins de Bourgogne, European Commission, Region Bourgogne-Franche-Comte, and Comite Champagne

Subjects
clone, vitis vinifera, [SDV]Life Sciences [q-bio], food and beverages, grapevine trunk diseases, metabolomics
Abstract

National audience; Esca is one of the most widespread grapevine trunk diseases affecting vineyards. This complex disease leads to leaf alterations, wood necrosis and eventually to plant death. Esca symptoms are caused by several fungi inhabiting the xylem of host plants and degrading the wood structure. The main pathogens causing the disease are Phaeomoniella chlamydospora, Phaeoacremonium minimum, Fomitiporia mediterranea and other wood-rotting basidiomycetes. Grapevine susceptibility to esca can be predisposed by several factors, especially climate, vine age, and cultivar. An experiment was carried out (in 2015) to assess if esca expression on leaves could also be clone-dependent. Chardonnay clones 76 and 95 grown in the same plot were compared according to their developmental and physiological traits, metabolome, and foliar symptom expression. Leaves were sampled during summer on visually healthy vines as controls (C), and from asymptomatic (D-) and symptomatic (D+) shoots of esca-affected vines. Analysis of their metabolomes highlighted a clone-dependent metabolite fingerprint associated to esca expression. Opposite variations of specific metabolites were found between C and D+ leaves of both clones. The experiment was repeated (in 2018). Leaf samples could be discriminated, especially the C and D+ samples for each clone, but the differences were less marked than in the first experiment. Discriminant compounds were all different between the two experiments, and showed no opposite variations between C and D+ samples of both clones, which indicated variable metabolite responses from year to year for both clones. These results confirm that the leaf metabolite fingerprint associated to esca expression is clone-dependent, and is year-dependent in intensity and nature.

Published
2020

18. A NEMO-based model of <i>Sargassum</i> distribution in the Tropical Atlantic: description of the model and sensitivity analysis (NEMO-Sarg1.0)

Author

Jouanno, Julien, primary, Benshila, Rachid, additional, Berline, Léo, additional, Soulié, Antonin, additional, Radenac, Marie-Hélène, additional, Morvan, Guillaume, additional, Diaz, Frédéric, additional, Sheinbaum, Julio, additional, Chevalier, Cristele, additional, Thibaut, Thierry, additional, Changeux, Thomas, additional, Menard, Frédéric, additional, Berthet, Sarah, additional, Aumont, Olivier, additional, Ethé, Christian, additional, Nabat, Pierre, additional, and Mallet, Marc, additional

Published
2020
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20. A NEMO-based model of Sargassum distribution in the tropical Atlantic: description of the model and sensitivity analysis (NEMO-Sarg1.0).

Author

Jouanno, Julien, Benshila, Rachid, Berline, Léo, Soulié, Antonin, Radenac, Marie-Hélène, Morvan, Guillaume, Diaz, Frédéric, Sheinbaum, Julio, Chevalier, Cristele, Thibaut, Thierry, Changeux, Thomas, Menard, Frédéric, Berthet, Sarah, Aumont, Olivier, Ethé, Christian, Nabat, Pierre, and Mallet, Marc

Subjects
SARGASSUM, SENSITIVITY analysis, ATMOSPHERIC deposition, SEASONS, LITTORAL drift
Abstract

The tropical Atlantic has been facing a massive proliferation of Sargassum since 2011, with severe environmental and socioeconomic impacts. The development of large-scale modeling of Sargassum transport and physiology is essential to clarify the link between Sargassum distribution and environmental conditions, and to lay the groundwork for a seasonal forecast at the scale of the tropical Atlantic basin. We developed a modeling framework based on the Nucleus for European Modelling of the Ocean (NEMO) ocean model, which integrates transport by currents and waves, and physiology of Sargassum with varying internal nutrients quota, and considers stranding at the coast. The model is initialized from basin-scale satellite observations, and performance was assessed over the year 2017. Model parameters are calibrated through the analysis of a large ensemble of simulations, and the sensitivity to forcing fields like riverine nutrient inputs, atmospheric deposition, and waves is discussed. Overall, results demonstrate the ability of the model to reproduce and forecast the seasonal cycle and large-scale distribution of Sargassum biomass. [ABSTRACT FROM AUTHOR]

Published
2021
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21. Clone-dependent expression of grapevine esca-disease. International congress on grapevine and wine research

Author

F, MORET, C, LEMAITRE-GUILLEC, G, CLMEENT, C, COELHO, J, NEGREL, R, GOUGEON, G, MORVAN, G, MOUILLE, M, ADRIAN, Moret, Florian, Lemaître-Guillier, Christelle, Grosjean, Claire, Clément, Gilles, Coelho, Christian, Negrel, Jonathan, Jacquens, Lucile, Morvan, Guillaume, MOUILLE, Grégory, Trouvelot, Sophie, Fontaine, Florence, Adrian, Marielle, Résistance Induite et Bioprotection des Plantes - EA 4707 (RIBP), Université de Reims Champagne-Ardenne (URCA)-SFR Condorcet, and Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV]Life Sciences [q-bio], food and beverages
Abstract

International audience; The occurrence of grapevine trunk diseases (GTDs) increases gradually within vineyards, leading to important economic losses. The worldwide cost of dead grapevines replacement is estimated over 1.5 billion dollars per year (Hofstetter et al., 2012). In France, close to 13% of the vineyard is affected (Bruez et al., 2013). Several factors could affect grapevine susceptibility to GTDs, mainly climate, vine age, soil fertilization, and also rootstock and variety (Surico et al., 2006). Presently, no cultivar tolerant to GTDs could be identified and the level of disease expression for a cultivar can vary with region and from year to year (Surico et al., 2006). In this context, our objective was to assess if the expression of esca disease, one of the most widespread GTDs, was clone-dependent.

Published
2018

23. Clone-Dependent Expression of Esca Disease Revealed by Leaf Metabolite Analysis

Author

Moret, Florian, primary, Lemaître-Guillier, Christelle, additional, Grosjean, Claire, additional, Clément, Gilles, additional, Coelho, Christian, additional, Negrel, Jonathan, additional, Jacquens, Lucile, additional, Morvan, Guillaume, additional, Mouille, Grégory, additional, Trouvelot, Sophie, additional, Fontaine, Florence, additional, and Adrian, Marielle, additional

Published
2019
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24. A NEMO-based model of Sargassum distribution in the Tropical Atlantic: description of the model and sensitivity analysis (NEMO-Sarg1.0).

Author

Jouanno, Julien, Benshila, Rachid, Berline, Léo, Soulié, Antonin, Radenac, Marie-Hélène, Morvan, Guillaume, Diaz, Frédéric, Sheinbaum, Julio, Chevalier, Cristele, Thibaut, Thierry, Changeux, Thomas, Menard, Frédéric, Berthet, Sarah, Aumont, Olivier, Ethé, Christian, Nabat, Pierre, and Mallet, Marc

Subjects
SARGASSUM, SENSITIVITY analysis, ATMOSPHERIC deposition, YEAR, LITTORAL drift
Abstract

The Tropical Atlantic is facing a massive proliferation of Sargassum since 2011, with severe environmental and socioeconomic impacts. The development of Sargassum modelling is essential to clarify the link between Sargassum distribution and environmental conditions, and to lay the groundwork for a seasonal forecast on the scale of the Tropical Atlantic basin. We developed a modelling framework based on the NEMO ocean model, which integrates transport by currents and waves, physiology of Sargassum with varying internal nutrients quota, and considers stranding at the coast. The model is initialized from basin scale satellite observations and performance was assessed over the Sargassum year 2017. Model parameters are calibrated through the analysis of a large ensemble of simulations, and the sensitivity to forcing fields like riverine nutrients inputs, atmospheric deposition, and waves is discussed. Overall, results demonstrate the ability of the model to reproduce and forecast the seasonal cycle and large-scale distribution of Sargassum biomass. [ABSTRACT FROM AUTHOR]

Published
2020
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25. On the improvement of wave and storm surge hindcasts by downscaled atmospheric forcing: application to historical storms

Author

Bresson, Émilie, primary, Arbogast, Philippe, additional, Aouf, Lotfi, additional, Paradis, Denis, additional, Kortcheva, Anna, additional, Bogatchev, Andrey, additional, Galabov, Vasko, additional, Dimitrova, Marieta, additional, Morvan, Guillaume, additional, Ohl, Patrick, additional, Tsenova, Boryana, additional, and Rabier, Florence, additional

Published
2018
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26. On the improvement of waves and storm surge hindcasts by downscaled atmospheric forcing: Application to historical storms

Author

Bresson, Émilie, primary, Arbogast, Philippe, additional, Aouf, Lotfi, additional, Paradis, Denis, additional, Kortcheva, Anna, additional, Bogatchev, Andrey, additional, Galabov, Vasko, additional, Dimitrova, Marieta, additional, Morvan, Guillaume, additional, Ohl, Patrick, additional, Tsenova, Boryana, additional, and Rabier, Florence, additional

Published
2017
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27. Skillful Seasonal Forecast of SargassumProliferation in the Tropical Atlantic

Author

Jouanno, Julien, Morvan, Guillaume, Berline, Léo, Benshila, Rachid, Aumont, Olivier, Sheinbaum, Julio, and Ménard, Frederic

Abstract

The large‐scale proliferation of pelagic Sargassumin the Tropical Atlantic from 2011 has been the subject of increasing attention because of its negative consequences on the environment, fishing, and socioeconomic activities when stranding on coastal areas. This recurrent phenomenon presents strong seasonal and year to year variations. Anticipating the abundances and stranding on seasonal scale poses important challenges in terms of observations and modeling. We show that skillful seasonal forecast of Sargassumdistribution can be achieved with up to 7 months in advance over the Tropical Atlantic, by integrating both transport and current knowledge on physiology of Sargassum. This forecast is designed to help marine stakeholders to develop mitigation and resilience strategies through anticipatory decision‐making. The Caribbean, Gulf of Mexico, and Tropical Atlantic are facing a massive and growing proliferation of floating brown algae (Sargassum) since 2011, whose environmental and socioeconomic impacts are immense. Observing, modeling, and forecasting the Sargassumproliferation and strandings are essential for designing effective integrated risk management strategies and is a strong and pressing demand from the civil society. The present study shows that a skillful forecast can be produced up to 7 months ahead of time by building on current knowledge on Sargassumphysiology, mechanistic modeling, and remote sensing observations. A transport and physiology model of pelagic Sargassumhas been developedSkillful seasonal forecast of Sargassumdistribution can be achieved with up to 7 months in advanceThis forecast extends the current Sargassumobservation and forecasting services A transport and physiology model of pelagic Sargassumhas been developed Skillful seasonal forecast of Sargassumdistribution can be achieved with up to 7 months in advance This forecast extends the current Sargassumobservation and forecasting services

Published
2023
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28. On the improvement of waves and storm surge hindcasts by downscaled atmospheric forcing: Application to historical storms.

Author

Bresson, Émilie, Arbogast, Philippe, Aouf, Lotfi, Paradis, Denis, Kortcheva, Anna, Bogatchev, Andrey, Galabov, Vasko, Dimitrova, Marieta, Morvan, Guillaume, Ohl, Patrick, Tsenova, Boryana, and Rabier, Florence

Subjects
STORM damage, STORM surges, WATER waves, WINDS, CLIMATE change
Abstract

Winds, waves and storm surges can induce severe damages in coastal areas. The FP7 IncREO project aims to understand the impact of climate change on coastal areas and also to assess the predictability of such extreme events. Reproduce efficiently past events is the fisrt step to reach this purpose. This paper shows the use of atmospheric downscaling techniques in order to improve waves and storm surge hindcasts. Past storms which caused damages on European coastal areas are investigated using atmosphere, wave and storm surge numerical models and downscaling techniques are based on existing ECMWF reanalyses. The results show clearly that the 10 km resolution wind forcing provided by the downscaled atmospheric model gives better waves and surges hindcast against using wind from the reanalysis. Furthermore, the analysis of the most extreme mid-latitude cyclones indicates that a 4D blending approach improves the whole process as it includes small scale processes in the initial conditions. [ABSTRACT FROM AUTHOR]

Published
2017
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