Altimetry for the future: Building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the ‘‘Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

Altimetry for the future: building on 25 years of progress

In 2018 we celebrated 25 years of development of radar altimetry, and the progress achieved by this methodology in the fields of global and coastal oceanography, hydrology, geodesy and cryospheric sciences. Many symbolic major events have celebrated these developments, e.g., in Venice, Italy, the 15th (2006) and 20th (2012) years of progress and more recently, in 2018, in Ponta Delgada, Portugal, 25 Years of Progress in Radar Altimetry. On this latter occasion it was decided to collect contributions of scientists, engineers and managers involved in the worldwide altimetry community to depict the state of altimetry and propose recommendations for the altimetry of the future. This paper summarizes contributions and recommendations that were collected and provides guidance for future mission design, research activities, and sustainable operational radar altimetry data exploitation. Recommendations provided are fundamental for optimizing further scientific and operational advances of oceanographic observations by altimetry, including requirements for spatial and temporal resolution of altimetric measurements, their accuracy and continuity. There are also new challenges and new openings mentioned in the paper that are particularly crucial for observations at higher latitudes, for coastal oceanography, for cryospheric studies and for hydrology. The paper starts with a general introduction followed by a section on Earth System Science including Ocean Dynamics, Sea Level, the Coastal Ocean, Hydrology, the Cryosphere and Polar Oceans and the “Green” Ocean, extending the frontier from biogeochemistry to marine ecology. Applications are described in a subsequent section, which covers Operational Oceanography, Weather, Hurricane Wave and Wind Forecasting, Climate projection. Instruments’ development and satellite missions’ evolutions are described in a fourth section. A fifth section covers the key observations that altimeters provide and their potential complements, from other Earth observation measurements to in situ data. Section 6 identifies the data and methods and provides some accuracy and resolution requirements for the wet tropospheric correction, the orbit and other geodetic requirements, the Mean Sea Surface, Geoid and Mean Dynamic Topography, Calibration and Validation, data accuracy, data access and handling (including the DUACS system). Section 7 brings a transversal view on scales, integration, artificial intelligence, and capacity building (education and training). Section 8 reviews the programmatic issues followed by a conclusion

L’empereur et le calife (690-695). Réflexions à propos des monnayages de Justinien II et d’Abd al-Malik

Morrisson Cécile, Prigent Vivien. L’empereur et le calife (690-695). Réflexions à propos des monnayages de Justinien II et d’Abd al-Malik. In: Topoi. Orient-Occident. Supplément 12, 2013. Villes et campagnes aux rives de la Méditerranée ancienne. Hommages à Georges Tate

« Les bulles de plomb du Musée national de Carthage, source méconnue pour l'histoire de l’Afrique byzantine (533-695/698) »

International audienc

La petite souris, une histoire de dents de lait dans la littérature pour la jeunesse

RENNES1-BU Santé (352382103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

L’empereur et le calife (690-695). Réflexions à propos des monnayages de Justinien II et d’Abd al-Malik

Morrisson Cécile, Prigent Vivien. L’empereur et le calife (690-695). Réflexions à propos des monnayages de Justinien II et d’Abd al-Malik. In: Topoi. Orient-Occident. Supplément 12, 2013. Villes et campagnes aux rives de la Méditerranée ancienne. Hommages à Georges Tate

Editorial for Special Issue “Mantle Strain Localization—How Minerals Deform at Deep Plate Interfaces”

International audienceUnderstanding Earth’s interior dynamics, the origin and factors of which maintain the present-day plate-like behavior of the lithosphere on our planet, is one of the main goals of geosciences [...

Les circuits courts alimentaires : des outils pour mieux agir. Guide pratique à destination des agents de développement

Guide en version interactive disponible ici : http://www.caprural.org/se-professionnaliser/sinformer/votre-boite-a-outils/3152-guide-pour-comprendre-et-accompagner-la-mise-en-place-de-circuits-courts-alimentairesLes décideurs leur portent une attention croissante. De leur côté, les acteurs du développement local, non spécialistes de la commercialisation, de l'agriculture ou de la consommation de produits alimentaires, doivent monter en connaissances et en compétences sur ce sujet. C'est en ce sens que la Plate-Forme régionale développement rural Rhône-Alpes et l'équipe du projet PSDR LiProCo ont élaboré un guide pratique à destination des professionnels du développement local, agents de développement notamment. Ce guide comporte trois parties : les circuits courts : entre définition et stratégie locale de développement ; les facteurs clés de succès : facteurs humains, logistiques et marketing ; les circuits courts : maîtriser les outils de diagnostic et les techniques d'enquête auprès des consommateurs

Fracture-mediated deep seawater flow and mantle hydration on oceanic transform faults

International audienceFluid-rock interaction on oceanic transform faults (OTFs) is important for both the deformation behavior of the lithosphere and volatile cycling in the Earth. Rocks deformed and exhumed at OTFs preserve information about the depth extent of fluid percolation and the nature of fluid-rock interactions within these fault zones. In this study, we focus on five dredges from the Shaka and Prince Edward OTFs on the ultraslow spreading Southwest Indian Ridge that recovered significant volumes of deformed mantle rocks. Samples are predominantly mylonites that have been deformed to high strains in the fault zone, but also contain several generations of fractures. Based on the mineral assemblages in fractures and shear bands combined with thermobarometry analysis, we identified three distinct temperature ranges of fluid-mantle interactions associated with deformation. At low temperature (LT), this leads to crystallization of serpentine (± talc ± amphibole ± chlorite) at <500-550°C. At medium temperature (MT), chlorite and amphibole crystallized at ~500-750°C. At high temperature (HT), amphibole (± second generation peridotitic minerals) crystallized. The composition of minerals in HT fractures and shear bands indicate that fracturing and fluid flow occur up to temperatures of at least 850-875°C. Combining these results with modeled geotherms for both faults suggests that seawater percolation extended to depths of 20-25 km and that serpentinization extended to ~11-13 km. The evolution of fault zone structure induced by deep fluid-rock interaction and progressive formation of LT, MT and HT mylonites on OTFs results in weakening and strain localization within the oceanic lithosphere, and suggests that the global transform system may represent a large reservoir of volatiles in the Earth's lithosphere