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Dense mantle flows periodically spaced below ocean basins / Isabelle Panet in Earth and planetary science letters, vol 594 (15 September 2022)  

Public [article]  inEarth and planetary science letters > vol 594 (15 September 2022) . - n° 117745 Titre : Dense mantle flows periodically spaced below ocean basins Type de document : Article/Communication Auteurs : Isabelle Panet , Auteur ; Marianne Greff-Lefftz, Auteur ; Barbara Romanowicz, Auteur Année de publication : 2022 Projets : Université de Paris / Clerici, Christine Article en page(s) : n° 117745 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] champ de pesanteur terrestre [Termes IGN] convection [Termes IGN] déformation de la croute terrestre [Termes IGN] dynamique des fluides [Termes IGN] fond marin [Termes IGN] Indien (océan) [Termes IGN] lithosphère [Termes IGN] manteau terrestre [Termes IGN] Pacifique (océan) Résumé : (auteur) Understanding mantle flow is key to elucidate how deep Earth dynamics relate to tectonics at the global scale. The convective mass transport is reflected in lateral variations of the gravity field, seismic velocities, as well as deformations of the Earth's surface. Yet, upper to mid-mantle dynamics have been difficult to constrain at the medium scales of thousands of km. Here, we analyze the second-order horizontal derivatives of seafloor topography and of the gravity potential over the Pacific and Northern Indian ocean basins, and provide evidence for periodic undulations of 1600-2000 km wavelength in both signals, elongated along the direction of absolute plate motion. We investigate potential crustal and lithospheric sources and show that at least part of this signal must originate below the lithosphere, with alignments of sub-lithospheric upper mantle mass excess below seafloor lows. Furthermore, we find that these alignments coincide geographically over wide areas with similarly periodic slow seismic velocity fingers located at upper mantle depths. These two fields may thus record an intermediate scale of mantle convection below ocean basins, which cannot be explained by purely thermal convection and requires instead lateral variations in composition in the upper mantle. Elucidating the nature of the detected mass excess sources coincident with the slow seismic velocities calls for a joint dynamical modeling of all observations in a thermo-chemical context. Numéro de notice : A2022-692 Affiliation des auteurs : UMR IPGP-Géod+Ext (2020- ) Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.epsl.2022.117745 En ligne : https://doi.org/10.1016/j.epsl.2022.117745 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=101809 [article]

The potential impact of hydrodynamic leveling on the quality of the European vertical reference frame / Yosra Afrasteh in Journal of geodesy, vol 95 n° 8 (August 2021)  

Public [article]  inJournal of geodesy > vol 95 n° 8 (August 2021) . - n° 90 Titre : The potential impact of hydrodynamic leveling on the quality of the European vertical reference frame Type de document : Article/Communication Auteurs : Yosra Afrasteh, Auteur ; D.C. Slobbe, Auteur ; M. Verlaan, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 90 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] données marégraphiques [Termes IGN] écart type [Termes IGN] European vertical GPS reference network [Termes IGN] hydrodynamique [Termes IGN] méthode heuristique [Termes IGN] niveau moyen des mers [Termes IGN] nivellement [Termes IGN] qualité des données [Termes IGN] réseau européen unifié de nivellement [Vedettes matières IGN] Altimétrie Résumé : (auteur) The first objective of this paper is to assess by means of geodetic network analyses the impact of adding model-based hydrodynamic leveling data to the Unified European Leveling Network (UELN) data on the precision and reliability of the European Vertical Reference Frame (EVRF). In doing so, we used variance information from the latest UELN adjustment. The model-based hydrodynamic leveling data are assumed to be obtained from not-yet existing hydrodynamic models covering either all European seas surrounding the European mainland or parts of it that provide the required mean water level with uniform precision. A heuristic search algorithm was implemented to identify the set of hydrodynamic leveling connections that provide the lowest median of the propagated height standard deviations. In the scenario in which we only allow for connections between tide gauges located in the same sea basin, all having a precision of 3 cm, the median of the propagated height standard deviations improved by 38% compared to the spirit leveling-only solution. Except for the countries around the Black Sea, coastal countries benefit the most with a maximum improvement of 60% for Great Britain. We also found decreased redundancy numbers for the observations in the coastal areas and over the entire Great Britain. Allowing for connections between tide gauges among all European seas increased the impact to 42%. Lowering the precision of the hydrodynamic leveling data lowers the impact. The results show, however, that even in case the assumed precision is 5 cm, the overall improvement is still 29%. The second objective is to identify which tide gauges are most profitable in terms of impact. Our results show that these are the ones located in Sweden in which most height markers are located. The impact, however, hardly depends on the geographic location of the tide gauges within a country. Numéro de notice : A2021-586 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-021-01543-3 Date de publication en ligne : 24/07/2021 En ligne : https://doi.org/10.1007/s00190-021-01543-3 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98203 [article]

A deep learning model using satellite ocean color and hydrodynamic model to estimate chlorophyll-a concentration / Daeyong Jin in Remote sensing, vol 13 n°10 (May-2 2021)  

Public [article]  inRemote sensing > vol 13 n°10 (May-2 2021) . - n° 2003 Titre : A deep learning model using satellite ocean color and hydrodynamic model to estimate chlorophyll-a concentration Type de document : Article/Communication Auteurs : Daeyong Jin, Auteur ; Eojin Lee, Auteur ; Kyonghwan Kwon, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 2003 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] apprentissage profond [Termes IGN] chlorophylle [Termes IGN] classification par réseau neuronal convolutif [Termes IGN] Corée du sud [Termes IGN] distribution spatiale [Termes IGN] données d'entrainement (apprentissage automatique) [Termes IGN] hydrodynamique [Termes IGN] image COMS-GOCI Résumé : (auteur) In this study, we used convolutional neural networks (CNNs)—which are well-known deep learning models suitable for image data processing—to estimate the temporal and spatial distribution of chlorophyll-a in a bay. The training data required the construction of a deep learning model acquired from the satellite ocean color and hydrodynamic model. Chlorophyll-a, total suspended sediment (TSS), visibility, and colored dissolved organic matter (CDOM) were extracted from the satellite ocean color data, and water level, currents, temperature, and salinity were generated from the hydrodynamic model. We developed CNN Model I—which estimates the concentration of chlorophyll-a using a 48 × 27 sized overall image—and CNN Model II—which uses a 7 × 7 segmented image. Because the CNN Model II conducts estimation using only data around the points of interest, the quantity of training data is more than 300 times larger than that of CNN Model I. Consequently, it was possible to extract and analyze the inherent patterns in the training data, improving the predictive ability of the deep learning model. The average root mean square error (RMSE), calculated by applying CNN Model II, was 0.191, and when the prediction was good, the coefficient of determination (R2) exceeded 0.91. Finally, we performed a sensitivity analysis, which revealed that CDOM is the most influential variable in estimating the spatiotemporal distribution of chlorophyll-a. Numéro de notice : A2021-417 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.3390/rs13102003 Date de publication en ligne : 20/05/2021 En ligne : https://doi.org/10.3390/rs13102003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97759 [article]

Dynamics of inundation events in the rivers-estuaries-ocean continuum in Bengal delta : synergy between hydrodynamic modelling and spaceborne remote sensing / Md Jamal Uddin Kahn (2021)  

Public Titre : Dynamics of inundation events in the rivers-estuaries-ocean continuum in Bengal delta : synergy between hydrodynamic modelling and spaceborne remote sensing Type de document : Thèse/HDR Auteurs : Md Jamal Uddin Kahn, Auteur ; Fabien Durand, Directeur de thèse ; Laurent Testut, Directeur de thèse Editeur : Toulouse : Université de Toulouse 3 Paul Sabatier Année de publication : 2021 Importance : 167 p. Format : 21 x 30 cm Note générale : Bibliographie Thèse présentée en vue de l’obtention du Doctorat en Océan, Atmosphère, Climat, de l’Université de Toulouse Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] Bengale, golfe du [Termes IGN] cyclone [Termes IGN] delta [Termes IGN] estran [Termes IGN] gestion des risques [Termes IGN] hydrodynamique [Termes IGN] image Sentinel-MSI [Termes IGN] marée océanique [Termes IGN] modèle numérique de surface [Termes IGN] niveau moyen des mers [Termes IGN] risque naturel [Termes IGN] submersion marine Index. décimale : THESE Thèses et HDR Résumé : (Auteur) The Bengal delta is the largest in the world. It is formed by the confluence of three transboundary rivers - Ganges, Brahmaputra, and Meghna. Flooding induced by large seasonal continental discharge, strong tide, and frequent deadly storm surges, regularly strikes this densely populated (density > 1000 person/km2), low-lying coastal region ( Note de contenu : 1. Introduction and Motivation 1.1 Introduction 1.2 The river deltas 1.3 Inundation in the Bengal delta 1.4 Bengal delta continuum and knowledge gaps 1.5 Scientific questions and study approach 1.6 Organization of the thesis 2. Hydrodynamic Modeling: Data and Methods 2.1 Introduction 2.2 Bathymetry assembly 2.3 Observations 2.4 Modelling framework 2.5 Model forcings and boundary condition 2.6 Assessment of tide 3. Intertidal Topography: Synergy Between Remote Sensing and Tidal Mod?elling 3.1 Introduction 3.2 Shoreline detection with Sentinel-2 imagery 3.3 Vertical referencing with tidal model 3.4 Results 3.5 Discussion 3.6 Conclusion 4. Coastal Tide: From the Present to the Future 4.1 Introduction 4.2 Observed trend in tidal range: The example of Hiron Point 4.3 Tidal model in the Bay of Bengal 4.4 Projected changes in tidal range in the Bengal delta 4.5 Tidal range evolution along the estuaries 4.6 Discussion 4.7 Conclusions 5. Storm Surge Modeling: A Case Study of Recent Super Cyclone Amphan 5.1 Introduction 5.2 Storm surge and inundation processes in the Bay of Bengal 5.3 Atmospheric evolution of cyclone Amphan 5.4 Storm surge model and performance 5.5 Near real-time storm surge forecasting 5.6 Discussion 5.7 Conclusions 5.8 Appendix 6. Storm Surge Hazard: A Probabilistic-Deterministic Approach 6.1 Introduction 6.2 Storm surge model 6.3 Probabilistic-deterministic cyclone ensemble 6.4 Storm surge hazard 6.5 Discussion 6.6 Conclusions and perspective 7. Conclusions and Perspectives for Future Work 7.1 Conclusion 7.2 Overview 7.3 Summary of conclusions and impacts 7.4 Future Research Perspectives 7.5 Transferrable lessons and concluding remarks Numéro de notice : 26768 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Thèse française Note de thèse : Thèse de Doctorat : Océan, Atmosphère, Climat : Toulouse : 2021 Organisme de stage : Laboratoire d'Etudes en Géophysique et Océanographie Spatiales LEGOS nature-HAL : Thèse DOI : sans Date de publication en ligne : 06/01/2022 En ligne : https://tel.hal.science/tel-03514722/ Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=99866

Hydrology / Theodore V. Hromadka II (2021)  

Public Titre : Hydrology Type de document : Monographie Auteurs : Theodore V. Hromadka II, Éditeur scientifique ; Prasada Rao, Éditeur scientifique Editeur : London [UK] : IntechOpen Année de publication : 2021 Importance : 122 p. Format : 19 x 27 cm ISBN/ISSN/EAN : 978-1-83962-331-8 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Hydrologie [Termes IGN] barrage [Termes IGN] changement climatique [Termes IGN] crue [Termes IGN] gestion de l'eau [Termes IGN] hydrodynamique [Termes IGN] hydrogéologie [Termes IGN] inondation [Termes IGN] modèle hydrographique [Termes IGN] précipitation [Termes IGN] sécheresse Résumé : (éditeur) In this book, an attempt is made to highlight the recent advances in Hydrology. The several topics examined in this book form the underpinnings of larger-scale considerations, including but not limited to topics such as large-scale hydrologic processes and the evolving field of Critical Zone Hydrology. Computational modeling, data collection, and visualization are additional subjects, among others, examined in the set of topics presented. Note de contenu : 1- Hydrometeorology: Review of past, present and future of methods 2- Perspectives of hydrologic modeling in agricultural research 3- Examination of hydrologic computer programs DHM and EDHM 4- Ecohydrology: An integrative sustainability science 5- Interlinking of river: Issues and challenges 6- Rivers of Lebanon: Significant water resources under threats 7- Statistical analysis of the precipitation isotope data with reference to the Indian subcontinent Numéro de notice : 28319 Affiliation des auteurs : non IGN Nature : Recueil / ouvrage collectif DOI : 10.5772/intechopen.87673 En ligne : https://doi.org/10.5772/intechopen.87673 Format de la ressource électronique : URL Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=98254

Using remote sensing and modeling to monitor and understand harmful algal blooms. Application to Karaoun Reservoir (Lebanon) / Najwa Sharaf (2021)  

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Intertidal topography mapping using the waterline method from Sentinel-1 & -2 images: The examples of Arcachon and Veys Bays in France / Edward Salameh in ISPRS Journal of photogrammetry and remote sensing, vol 163 (May 2020)  

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Le sol s'affaisse, l'eau monte [Delta du Gange-Brahmapoutre-Meghna] / Marielle Mayo in Géomètre, n° 2179 (avril 2020)

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Sea surface roughness observed by high resolution radar / Atsushi Fujimura (2019)  

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A study of the influence of the historical snow accumulation and wind effects on the extended Chajnantor plateau / Juliette Ortet (2018) 

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The Use of remote sensing in hydrology / Frédéric Frappart (2018)  

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Toward a systematic integration of optical remote sensing for inland waters studies / Vincent Maurice Nouchi (2018)  

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Estimation of 3-D surface displacement based on InSAR and deformation modeling / Jun Hu in IEEE Transactions on geoscience and remote sensing, vol 55 n° 4 (April 2017)  

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Using virtual reality and percolation theory to visualize fluid flow in porous media / Carlos Magno De Lima in Geoinformatica, vol 17 n° 4 (October 2013)  

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Computational Physics / Philipp Scherer (2013)  

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