Marine Herrmann

Marine Herrmann
Institute of Research for Development | IRD · 065 - Laboratory for Studies in Geophysics and Spatial Oceanography (LEGOS)

PhD in Oceanography

About

85
Publications
25,352
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3,314
Citations

Publications

Publications (85)
Article
Full-text available
The Northwestern Mediterranean Sea (NWMS) is biologically one of the most productive Mediterranean regions. NWMS pelagic planktonic ecosystem is strongly influenced by hydrodynamics, in particular by deep convection, that could significantly weaken under the influence of climate change. Here we investigate the response of this ecosystem and associa...
Article
Full-text available
Deep convection (DC) is a key-process of the oceanic circulation, costly to monitor in situ and under the influence of climate change. Our study is a first step toward monitoring DC from space: we investigate the feasibility of observing its variability using improved satellite altimetry. An oceanic simulation of the Mediterranean circulation was p...
Article
Full-text available
In the northwestern Mediterranean Sea, winter 1986-1987 was particularly cold, inducing a strong open ocean convection event. In order to investigate the impact of numerical models spatial resolution on the convection representation and the effects of deep convection on the northwestern Mediterranean circulation, we perform two numerical three-dime...
Article
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Dense water formed over the continental shelf and cascading down the slope is responsible for shelf-slope exchanges in many parts of the world ocean, and transports large amounts of sediment and organic matter into the deep ocean. Here we perform numerical modeling experiments to investigate the impact of atmospheric interannual variability and cli...
Article
Full-text available
Open-sea convection occurring in the northwestern Mediterranean basin (NWMED) is at the origin of the formation of Western Mediterranean Deep Water (WMDW), one of the main Mediterranean water masses. During winter 2004–2005, a spectacular convection event occurred, observed by several experimental oceanographers. It was associated with an exception...
Article
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The role of mixing between layers of different densities is key to how the ocean works and interacts with other components of the Earth's system. Correctly accounting for its effect in numerical simulations is therefore of utmost importance. However, numerical models are still plagued with spurious sources of mixing, originating mostly from the ver...
Article
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Summer monsoon southwest wind induces the South Vietnam Upwelling (SVU) over four main areas along the southern and central Vietnamese coast: upwelling offshore of the Mekong shelf (MKU), along the southern and northern coasts (SCU and NCU), and offshore (OFU). Previous studies have highlighted the roles of wind and ocean intrinsic variability (OIV...
Preprint
Full-text available
The role of mixing between layers of different density is key to how the ocean works and interacts with other components of the Earth System. Accounting correctly for its effect in numerical simulations is therefore of utmost importance. However, numerical models are still plagued with spurious sources of mixing, originating mostly from the vertica...
Article
Full-text available
The South China Sea throughflow (SCSTF) connects the South China Sea (SCS) with neighboring seas and oceans, transferring surface water of the global thermohaline circulation between the Pacific and Indian oceans. A configuration of the SYMPHONIE ocean model at high resolution (4 km) and including an explicit representation of tides is implemented...
Preprint
Full-text available
Summer monsoon southwest wind induces the South Vietnam Upwelling (SVU) over four main areas along the southern and central Vietnamese coast: offshore the Mekong shelf (MKU), along the Southern and Northern coasts (SCU and NCU) and offshore (OFU). Previous studies have highlighted the roles of wind and Ocean Intrinsic Variability (OIV) in the SVU i...
Article
Fluvial organic carbon (OC) transfer is an essential resource for downstream ecosystems. Multiple factors affect its transfer process, e.g., climate or anthropogenic activities. Quantifying OC fluxes with fine spatiotemporal resolution is challenging in anthropised catchments. This study aims to quantify daily OC dynamics and to assess the impacts...
Preprint
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River freshwater fluxes are fundamental inputs for regional and global ocean models. Nonetheless, most models are currently forced by climatological runoff data, encompassing several limitations and resulting in significant biases in the simulated ocean conditions. This study evaluates daily river discharge into South East Asia (SEA), a region havi...
Preprint
Full-text available
The South China Sea Throughflow (SCSTF) connects the South China Sea (SCS) with neighboring seas and oceans, transferring surface water of the global thermohaline circulation between the Pacific and Indian oceans. A high resolution (4 km, 50 vertical levels) configuration of the SYMPHONIE ocean model is implemented over this region, and a simulatio...
Article
Full-text available
The South Vietnam upwelling (SVU) develops off the Vietnamese coast (South China Sea, SCS) during the southwest summer monsoon over four main areas: the northern coastal upwelling (NCU), the southern coastal upwelling (SCU), the offshore upwelling (OFU) and the shelf off the Mekong River mouth (MKU). An ensemble of 10 simulations with perturbed ini...
Article
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This study investigates the impact of El Niño Southern Oscillation (ENSO) and ENSO Modoki on rainfall variability over Southeast Asia (SEA) with a focus on its twenty sub-regions. For the period 1979–2019, seven El Niño (EN), six La Niña (LN), five El Niño Modoki (EM), and five La Niña Modoki (LM) events were identified. In the boreal summer (JJA)...
Preprint
Full-text available
The South Vietnam Upwelling (SVU) develops off the Vietnamese coast (South China Sea) during the southwest summer monsoon over four main areas: the northern coastal upwelling (NCU), the southern coastal upwelling (SCU), the offshore upwelling (OFU) and the shelf off the Mekong River mouth (MKU). An ensemble of ten simulations with perturbed initial...
Poster
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Based on the mutual support from the Agence Francaise de Développement (AFD) and the French National Research Institute for Sustainable Development (IRD), a collaborative research project conducted jointly by the Indonesian Ministry of Marine Affairs and Fisheries (KKP), CLS and IRD aims to sustain the monitoring and modelling of marine debris in t...
Article
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The South Vietnam Upwelling (SVU) develops in the South China Sea (SCS) under the influence of southwest monsoon winds. To study the role of small spatiotemporal scales on the SVU functioning and variability, a simulation was performed over 2009–2018 with a high-resolution configuration (1 km at the coast) of the SYMPHONIE model implemented over th...
Poster
Full-text available
Air-sea freshwater fluxes affect the ocean salinity and the resulting upper layers stratification that critically contributes to the density-driven global ocean circulation and to the climate variability. Regionally, river runoffs or plumes play also a key role for the local stratification, by interacting with the local ocean dynamics and eddies at...
Article
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In this research, rice husk-derived biochar (BC) was evaluated to determine the suitable conditions for the methylene blue (MB) solution adsorption. The characterization of BC was identified by the methods of FT-IR, Raman, and point of zero charges (PZC). The adsorption studies were carried out with BC at different activation conditions (raw BC, HN...
Preprint
Full-text available
The South Vietnam Upwelling (SVU) develops in the South China Sea off the Vietnamese coast under the influence of southwest monsoon winds. A very high resolution configuration (1 km at the coast) of the SYMPHONIE model was developed over the western coastal region of the South China Sea. A simulation was performed over the period 2009–2018 to study...
Article
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Numerical representation and climate projections of sea surface winds over Southeast Asia (SEA) are assessed here using an ensemble of the Coupled Model Intercomparison Project Phase 5 (CMIP5) downscaled simulations performed over the 20th and 21st centuries under Representative Concentration Pathways (RCPs) 4.5 and 8.5 scenarios within the Coordin...
Article
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In this study, titanium dioxide (TiO2) nanoparticles are immobilized onto rice husk biochar (RHB), as a porous support, for the photodegradation of glyphosate under UV light irradiation. The TiO2/RHB composites are prepared by pyrolysis and the sol-gel method. The SEM, XRD, EDX, and FT-IR results confirm the graphene structure of RHB and the format...
Article
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We study the daily to interannual variability of the Red River plume in the Gulf of Tonkin from numerical simulations at high resolution over 6 years (2011–2016). Compared with observational data, the model results show good performance. To identify the plume, passive tracers are used in order to (1) help distinguish the freshwater coming from diff...
Article
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In this study, biochar was derived from the agricultural by-products coconut coir (BC1) and rice husk (BC2) activated with NaOH 25%. This material was characterized through analytical methods such as SEM images, XRD, FTIR, and Raman. Analysis results indicated that the carbon structure carbon is amorphous and with many graphene layers. A high speci...
Conference Paper
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In our modern world, plastics are everywhere in the daily life and they are also the most abundant type of litter or discarded solid waste, in particular in the marine environment. The situation results in a persistent, ubiquitous presence of plastics in the world ocean. Consequently, plastics in their different forms represents the most pressing e...
Article
A new green method for trace level quantification of four herbicides, glyphosate (GLYP), glufosinate (GLUF), and their main metabolites, aminomethylphosphonic acid (AMPA) and 3-(methyl-phosphinico)-propionic acid (MPPA), was developed. The purification step without any derivatization was conducted by solid-phase extraction using Chelex-100 resin in...
Article
The present study explores the seasonal variability of the circulation in the Gulf of Tonkin (GoT) and associated water fluxes, and identifies the driving physical processes of this circulation. We use a 9 year (2009–2017)high-resolution numerical simulation. It is evaluated with historical hydrographic data, sea level data, high-frequency radar da...
Article
Abstract : Abstract Here, we simulate carbon dioxide (CO2) sequestration in 300 major world river basins (about 70% of global surface area) through carbonates dissolution and silicate hydrolysis. For each river basin, the daily timescale impacts under both the RCP 2.6 and RCP 8.5 climate scenarios were assessed relative to a historic baseline (1969...
Article
The Red River is an Asian river system strongly affected by global changes. This paper aims to characterize and quantify the suspended sediment flux (SF) over the basin under the influences of short-term climate variability and dam constructions. SF was evaluated at the outlets of main tributaries and along the main course of the Red River from 200...
Article
This study explores the seasonal and tidal changes in flow and suspended matter dynamics in the tropical and macrotidal Van Uc River estuary (North Vietnam) and aims at understanding, among others, the sediment delivery to the ocean and the processes behind the estuarine siltation. Four campaigns took place during the contrasting high flow and low...
Article
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Consequences of tidal dynamics on hydro-sedimentary processes are a recurrent issue in estuarine and coastal processes studies, and accurate tidal solutions are a prerequisite for modeling sediment transport, especially in macro-tidal regions. The motivation for the study presented in this publication is to implement and optimize a model configurat...
Article
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Southeast Asia (SEA) climate shows a large range of variability scales, from extreme events to interannual variability. Understanding its answer to climate change is of primary scientific and socio-economic importance. IPCC 5th assessment report however pointed the lack of knowledge in regional climate change and its impact in SEA. In particular li...
Article
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The summer South Vietnam Upwelling (SVU) is a major component of the South China Sea circulation where it also influences ecosystems. Here we revisit the existing knowledge of the SVU interannual variability. Based on a set of 15‐year eddy‐resolving sensitivity simulations, we quantify the respective contributions from different factors (atmospheri...
Article
Full-text available
Tidal dynamics consequences on hydro-sedimentary processes are a recurrent issue in estuarine and coastal processes studies and accurate tidal solutions are a prerequisite for modelling sediment transport, especially in macro-tidal regions. The motivation for the study presented in this publication is to implement and optimize the model configurati...
Article
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Observing, modelling and understanding the climate-scale variability of the deep water formation (DWF) in the North-Western Mediterranean Sea remains today very challenging. In this study, we first characterize the interannual variability of this phenomenon by a thorough reanalysis of observations in order to establish reference time series. These...
Article
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Chaotic intrinsic variability is a fundamental driver of the oceanic variability. Its understanding is key to interpret observations, evaluate numerical models and predict the future ocean and climate. Here we study intrinsic variability of deep convection in the Northwestern Mediterranean Sea using an ensemble eddy-resolving hindcast simulation ov...
Article
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Winter 2012-2013 was a particularly intense and well-observed Dense Water Formation (DWF) event in the Northwestern Mediterranean Sea. In this study, we investigate the impact of the mesoscale dynamics on DWF. We perform two perturbed initial state simulation ensembles from summer 2012 to 2013, respectively mesoscale-permitting and mesoscale-resolv...
Article
Spatio-temporal patterns of the chlorophyll-a concentration, Chla, have been assessed fromtheMEdiumResolution Imaging Spectrometer (MERIS) over the whole Vietnamese coastal waters from 2002 to 2012. For that purpose, six bio-optical algorithms already documented and based on different approaches have been tested over a large in situ data set collec...
Article
Full-text available
Deep convection occurs in oceanic regions submitted to strong atmospheric buoyancy losses and results in the formation of deep water masses (DWF) of the ocean circulation. It shows a strong interannual variability, and could drastically weaken under the influence of climate change. In this study, a method is proposed to monitor quantitatively deep...
Article
Full-text available
The northwestern Mediterranean Sea is a well-observed ocean deep convection site. Winter 2012-2013 was an intense and intensely documented dense water formation (DWF) event. We evaluate this DWF event in an ensemble configuration of the regional ocean model NEMOMED12. We then assess for the first time the impact of ocean intrinsic variability on DW...
Article
A 3D hydrodynamic-biogeochemical coupled model has been used to estimate a budget of organic carbon and its interannual variability over the 5-year period 2004-2008 in the North-Western Mediterranean Open Sea (NWMOS). The comparison of its results with in situ and satellite observations reveals that the timing and the magnitude of the convection an...
Article
Full-text available
The northwestern Mediterranean (NWMed) sea includes one of the best observed ocean deep convection sites in the World. An Observing System Simulation Experiment (OSSE) is developed to provide a methodology for estimating observing network errors. It is applied to quantify dense water volumes in the NWMed during 2012-2013 with their observation erro...
Article
Full-text available
The Mediterranean climate is expected to become warmer and drier during the twenty-first century. Mediterranean Sea response to climate change could be modulated by the choice of the socio-economic scenario as well as the choice of the boundary conditions mainly the Atlantic hydrography, the river runoff and the atmospheric fluxes. To assess and qu...
Article
Full-text available
The Northwestern Mediterranean Sea (NWMS) is one of the most productive areas of the Mediterranean Sea. The NWMS pelagic planktonic ecosystem is strongly influenced by hydrodynamics, in particular winter deep convection. Here, we investigate the response of this ecosystem and associated carbon cycle to oceanic and atmospheric winter conditions inte...
Conference Paper
Full-text available
The North-Western Mediterranean Sea is known as one of the only place in the world where open-sea deep convection occurs (often up to more than 2000m) with the formation of the Western Mediterranean Deep Water (WMDW). This phenomena is mostly driven by local preconditioning of the water column and strong buoyancy losses during Winter. At the event...
Chapter
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The aim of this chapter is to introduce the main topics in the Mediterranean circulation research and to give a general description of the Mediterranean Sea variability. Its scope is to provide information that is important for a comprehensive view of the most relevant issues concerning climate, which is a coupling between atmosphere and sea. The c...
Article
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ERA-40 reanalyses, and simulations from three regional climate models (RCMs) (ALADIN, LMDZ, and WRF) and from one statistical downscaling model (CDF-t) are used to evaluate the uncertainty in downscaling of wind, temperature, and rainfall cumulative distribution functions (CDFs) for eight stations in the French Mediterranean basin over 1991-2000. T...
Conference Paper
Following the IPCC scenarios (Gibelin and Déqué 2003, Giorgi 2006, IPCC 2007, Somot et al. 2008), the climate over the Mediterranean basin is foreseen to become warmer and drier during the 21st century. In terms of density, these two effects may have an opposite impact on the Mediterranean Sea surface waters (warmer and saltier), the winter ocean d...
Conference Paper
Significant differences in the Mediterranean Sea water characteristics are foreseen to appear during twenty first century, as reported in the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC, 2007). Main changes could be a warmer and drier ocean that would lead to warming and saltening waters. Mean sea level increase,...
Article
An original implementation of a non-hydrostatic, free-surface algorithm based on a pressure correction method is proposed for ocean modelling. The free surface is implemented through an explicit scheme combined with a mode-spitting method but the depth-averaged velocity and the position of the free surface are updated at each non-hydrostatic iterat...
Article
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Atmospheric datasets coming from long term reanalyzes of low spatial resolution are used for different purposes. Wind over the sea is, for example, a major ingredient of oceanic simulations. However, the shortcomings of those datasets prevent them from being used without an adequate corrective preliminary treatment. Using a regional climate model (...
Article
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La Méditerranée nord-occidentale (MNO) constitue un formidable laboratoire d'étude des deux processus responsables de la formation d'eau dense dans l'océan : le cascading et la convection profonde. Un outil de modélisation de la dynamique océanique en MNO et de son influence sur les écosystèmes marins a été mis en The Northwestern Mediterranean Sea...
Article
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The recent major production of anomalously warm, salty deep water in the northwestern Mediterranean Sea (winters 2004–2005 and 2005–2006) is linked to extreme winter air-sea heat and freshwater forcing of the basin. Fields of heat and density fluxes are determined both from the National Centers for Environmental Prediction-National Center for Atmos...
Article
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This work is dedicated to the study of the climate variability of the Mediterranean Sea, in particular the study of the Eastern Mediterranean Transient (EMT) which occurred in the early 1990s. Simulations of the 1961-2000 period have been carried out with an eddy-permitting Ocean General Circulation Model of the Mediterranean Sea, driven by realist...
Article
This paper proposes an original approach of the open boundary condition problem, within the framework of internal hydrostatic wave theory. These boundary conditions are based on the relations of polarization of internal waves. The method is presented progressively, beginning with a simple case (non-rotating regime, propagation direction normal to t...
Article
Full-text available
We present an atmosphere–ocean regional climate model for the Mediterranean basin, called the PROTHEUS system, composed by the regional climate model RegCM3 as the atmospheric component and by a regional configuration of the MITgcm model as the oceanic component. The model is applied to an area encompassing the Mediterranean Sea and compared to a s...
Article
An eddy-permitting model of View the MathML source resolution is implemented covering the whole Mediterranean Sea. Within this grid a View the MathML source resolution model of the Strait of Gibraltar is embedded. The two grids belong to different models that are coupled through an external parallel driver. The robustness of the adopted grid refine...
Article
The Mediterranean Sea can be considered as a thermodynamic machine that exchanges water and heat with the Atlantic Ocean through the Strait of Gibraltar and with the atmosphere through its surface. Considering the Mediterranean Sea Water Budget (MSWB) multi-year mean, the Mediterranean basin looses water at the surface due to an excess of evaporati...