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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]

Mapping burned areas and land-uses in Kangaroo Island using an object-based image classification framework and Landsat 8 Imagery from Google Earth Engine / Jiyu Liu in Geomatics, Natural Hazards and Risk, vol 13 (2022)  

Public [article]  inGeomatics, Natural Hazards and Risk > vol 13 (2022) . - pp 1867 - 1897 Titre : Mapping burned areas and land-uses in Kangaroo Island using an object-based image classification framework and Landsat 8 Imagery from Google Earth Engine Type de document : Article/Communication Auteurs : Jiyu Liu, Auteur ; David Freudenberger, Auteur ; Lim Samsung, Auteur Année de publication : 2022 Article en page(s) : pp 1867 - 1897 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] analyse d'image orientée objet [Termes IGN] analyse spectrale [Termes IGN] approche hiérarchique [Termes IGN] Australie [Termes IGN] carte thématique [Termes IGN] écosystème forestier [Termes IGN] Google Earth Engine [Termes IGN] image infrarouge [Termes IGN] image Landsat-8 [Termes IGN] incendie [Termes IGN] Indien (océan) [Termes IGN] segmentation d'image [Termes IGN] utilisation du sol [Termes IGN] zone sinistrée Résumé : (auteur) In Australia, fire has become part of the natural ecosystem. Severe fires have devastated Australia's unique forest ecosystems due to the global climate change. In this study, we integrated a multi-resolution segmentation method and a hierarchical classification framework based on expert-based knowledge to classify the burned areas and land-uses in Kangaroo Island, South Australia. Using an object-based image classification framework that combines colour and shape features from input layers, we demonstrated that the objects segmented from the multi-source data lead to a higher accuracy in classification with an overall accuracy of 90.2% and a kappa coefficient of 85.2%. On the other hand, the single source data from post-fire Landsat-8 imagery showed an overall accuracy of 87.4% which is also statistically acceptable. According to our experiment results, more than 30.44% of the study area was burned during the 2019–2020 ‘Black-Summer’ fire season in Australia. Among the burned areas, high severity accounted for 12.14%, moderate severity for 11.48%, while low severity was 6.82%. For unburned areas, farmland accounted for 45.52% of the study area, of which about one-third was affected by the disturbances other than fire. The remaining area consists of 19.42% unaffected forest, 3.48% building and bare land, and 1.14% water. The comparison analysis shows that our object-based image classification framework takes full advantage of the multi-source data and generates the edges of burned areas more clearly, which contributes to the improved fire management and control. Numéro de notice : A2022-873 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article DOI : 10.1080/19475705.2022.2098066 Date de publication en ligne : 02/08/2022 En ligne : https://doi.org/10.1080/19475705.2022.2098066 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=102171 [article]

Assessment of mass-induced sea level variability in the Tropical Indian Ocean based on GRACE and altimeter observations / Shiva Shankar Manche in Journal of geodesy, vol 95 n° 2 (February 2021)  

Public [article]  inJournal of geodesy > vol 95 n° 2 (February 2021) . - n° 19 Titre : Assessment of mass-induced sea level variability in the Tropical Indian Ocean based on GRACE and altimeter observations Type de document : Article/Communication Auteurs : Shiva Shankar Manche, Auteur ; Rabindra K. Nayak, Auteur ; Prakash Chandra Mohanty, Auteur ; et al., Auteur Année de publication : 2021 Article en page(s) : n° 19 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Géodésie physique [Termes IGN] analyse harmonique [Termes IGN] changement climatique [Termes IGN] données altimétriques [Termes IGN] données GRACE [Termes IGN] Indien (océan) [Termes IGN] masse d'eau [Termes IGN] modèle océanographique [Termes IGN] niveau de la mer [Termes IGN] surcharge océanique [Termes IGN] variabilité [Termes IGN] variation saisonnière Résumé : (auteur) Assessment of mass-induced sea level (MISL) variability in the Tropical Indian Ocean (TIO) was studied using observations from the Gravity Recovery and Climate Experiment (GRACE) during 2003–2017 in conjunction with the steric effects in the sea level anomaly as measured by satellite altimeters. Two steric sea levels were estimated from the ocean model analysis and Argo gridded temperature and salinity fields. These datasets were consistent with each other and to the altimeter measured sea level records. They exhibited a coherent seasonal cycle with unique spatial patterns of amplitude maxima associated with annual and semi-annual harmonics. Steric component remained as a major contributor to the sea level variability at all the time scales. Addition of the GRACE measured MISL to the steric sea level improved the estimation of sea level (as measured by satellite altimeter) over most part of the TIO except over the northern part of the Arabian Sea. It was observed that the MISL had a significant contribution to the sea level variability at intra-seasonal and seasonal time scales and a minor contribution to the sea level inter-annual variability. During all the El Niño years, sea level underwent a large fluctuation coherent to the steric component. A linear barotropic vortex conservation model driven by ocean surface winds explained a major part of the observed MISL high-frequency variability in the Equatorial and southern TIO, and overestimated the observation in the northern TIO. Numéro de notice : A2021-137 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1007/s00190-021-01471-2 Date de publication en ligne : 31/01/2021 En ligne : https://doi.org/10.1007/s00190-021-01471-2 Format de la ressource électronique : url article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=97010 [article]

Comparing the performance of turbulent kinetic energy and K-profile parameterization vertical parameterization schemes over the tropical indian ocean / Lokesh Kumar Pandey in Marine geodesy, vol 44 n° 1 (January 2021)  

Public [article]  inMarine geodesy > vol 44 n° 1 (January 2021) . - pp 42 - 69 Titre : Comparing the performance of turbulent kinetic energy and K-profile parameterization vertical parameterization schemes over the tropical indian ocean Type de document : Article/Communication Auteurs : Lokesh Kumar Pandey, Auteur ; Suneet Dwivedi, Auteur Année de publication : 2021 Article en page(s) : pp 42 - 69 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Océanographie [Termes IGN] Bengale, golfe du [Termes IGN] énergie cinétique [Termes IGN] Indien (océan) [Termes IGN] modélisation spatiale [Termes IGN] mousson [Termes IGN] salinité [Termes IGN] température de surface de la mer Résumé : (Auteur) The performance of vertical parameterization schemes, namely, turbulent kinetic energy (TKE) and K-profile parameterization (KPP), is evaluated over the domain [30E-120E; 20S-30N] in the Indian Ocean using the Nucleus for European Modeling of the Ocean (NEMO) regional model. The surface and sub-surface hydrography and mixed layer depth (MLD) of the simulations using TKE and KPP schemes have been compared. The KPP scheme produces higher bias (∼0.5 °C) of sea surface temperature (SST) in monsoon and post-monsoon seasons, which reduces on using the TKE scheme. The maximum surface salinity difference (0.45 psu) between TKE and KPP simulations is obtained over the head Bay of Bengal (BoB) in the post-monsoon months. The KPP scheme also overestimates MLD of the region. Barring highly convective regions as well as regions marked with very low and rapidly changing salinity, the TKE scheme performs better than KPP scheme in simulating the hydrography and MLD of the region. The differences between TKE and KPP simulations in the vertical stability and mixing are studied using buoyancy frequency, vertical shear of horizontal currents and energy required for mixing as quantifiers. The mixed layer heat budget analysis explains seasonal variability of SST and differences in vertical mixing parameterizations. Numéro de notice : A2021-059 Affiliation des auteurs : non IGN Thématique : POSITIONNEMENT Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/01490419.2020.1835758 Date de publication en ligne : 29/10/2020 En ligne : https://doi.org/10.1080/01490419.2020.1835758 Format de la ressource électronique : URL Article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=96849 [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

Impact of INSAT-3D/3DR radiance data assimilation in predicting tropical cyclone Titli over the bay of Bengal / Raghu Nadimpalli in IEEE Transactions on geoscience and remote sensing, vol 58 n° 10 (October 2020)  

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Joint inversion of GPS and high-resolution GRACE gravity data for the 2012 Wharton basin earthquakes / Michel Diament in Journal of geodynamics, vol 136 (May 2020)  

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Optimal lowest astronomical tide estimation using maximum likelihood estimator with multiple ocean models hybridization / Mohammed El-Diasty in ISPRS International journal of geo-information, vol 9 n° 5 (May 2020)  

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Étude de la vapeur d’eau atmosphérique à partir de données GNSS dans le bassin sud-ouest de l’océan Indien et applications à l’étude du climat et des cyclones tropicaux / Edouard Lees (2020)  

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New quantitative indices from 3D modeling by photogrammetry to monitor coral reef environments / Isabel Urbina-Barreto (2020)  

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Sea level variation around Australia and its relation to climate indices / Armin Agha Karimi in Marine geodesy, vol 42 n° 5 (September 2019)  

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Reconciling upper mantle seismic velocity and density structure below ocean basins / Isabelle Panet (2019)

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Sea surface salinity remote sensing / Emmanuel P. Dinnat (2019)  

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Extension of satellite altimetry Jason-2 sea level anomalies towards the Red Sea coast using polynomial harmonic techniques / A. M. Taqi in Marine geodesy, vol 40 n° 5 (September 2017)  

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Mass evolution of Mediterranean, Black, Red, and Caspian Seas from GRACE and altimetry : accuracy assessment and solution calibration / B. D. Loomis in Journal of geodesy, vol 91 n° 2 (February 2017)  

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