Search results for "Universe"
showing 10 items of 2171 documents
Étude climatique de la mousson vietnamienne et applications à la prévision saisonnière
2008
This thesis aims at documenting the physical and dynamic processes associated with the monsoon circulation of Vietnamese regional and synoptic scales, to explore the predictability of its key components and develop statistical and dynamical methods for forecasting the monsoon onset and seasonal. It is divided into two parts. The first part is, in fact, a climate study based on analysis of diagnostic data: - first, the monthly rainfall and temperature data station over the period 1960-2000 are used to analyze the cycle and the variability of these fields on the seven traditional climatic regions of Vietnam using the observed precipitation in various stations. Classifications and correlations…
Événements hydroclimatiques et risque d’inondation au sud-ouest du Bénin.
2011
6 pages; International audience; Depuis la décennie 1990, le golfe de Guinée et le sud-ouest du Bénin connaît des inondations récurrentes. Ainsi,en 1999, 2007, 2009 et 2010, des inondations de grande envergure ont affecté les communes des régions littorales et sublittoralesdu Bénin, en particulier celles parcourues par le fleuve Mono, avec déplacement des populations. L’analyses’appuie sur les données mensuelles des pluies et du débit du Mono à Athiémé et du Couffo à Lanta, ainsi que sur lesobservations de terrain dans la basse vallée. Sur la période 1991-2010, les épisodes de fortes crues sont identifiés. L’analysestatistique fait ressortir une légère augmentation des précipitations depuis…
Signatures terrigène et volcanique des bassins sédimentaires : implications stratigraphiques et paléoclimatiques
2018
Temporal evolution of heavy rainfall in the southern West Africa coastline belt.
2018
The Southern Coastalbelt of West Africa (SCWA) is exposed to recurrent flooding. The two objectives of the study are to show thespecificity of SCWA to heavy rainfall occurrence and to determine the trends of the latter. Daily rainfall data of41 stations in the southern parts of Côte d’Ivoire, Ghana, Togo and Benin for the period 1951–2015 and ClimateHazards Group InfraRed Precipitation data were used. The approach is based on the determination (for eachstation and grid point) of the 95th centile (P95) of precipitations greater than or equal to 1 mm. Results indicatethat rainfall is heavier on the coastal belt than inland (average P95 is 65,4 and 45,5 m/day for coastal and inlandstations res…
Mesure des émissions de CO2 en milieu urbain : étude du flux et de ses variations à l’aide des isotopes du carbone.
2013
7 pages; International audience; Dans la ville de Dijon, les émissions de CO2 ont été mesurées. Les variations de la concentration atmosphériquesen CO2 et de la signature isotopiques du CO2 atmosphérique ont permis de mettre en évidence un dôme urbain au dessus dela ville. Ce dôme présente un double mécanisme lié au trafic et à la respiration du sol. Le niveau de base des dômes sesitue sur une droite de mélange (ou une courbe) ayant pour origine les valeurs de la concentration (370 ppm) et du d13C (-8‰) mesurées en zone rurale ainsi que la droite de mélange du trafic. La concentration et la signature isotopique dépendaussi de la respiration du sol. D’autre paramètre comme la température et …
The relationship between copper accumulated in vineyard calcareous soils and soil organic matter and iron
2002
International audience; The intensive use for over 100 yr of copper sulfate (Bordeaux mixt.) to fight mildew in vineyards has led to a substantial accumulation of copper (Cu) in surface soils. To assess the effects of such large concns., the surface soils of 10 Burgundy vineyards were sampled and analyzed for total org. matter (carbon and nitrogen) and metal (copper and iron) contents. Phys. (i.e. size fractionation) and chem. (sequential extn.) methods were used to det. the distribution of these elements. The most Cu-contaminated plots showed the largest accumulation of org. carbon and Cu in the coarse sand and fine sand fractions. Copper was strongly correlated with org. carbon and org. …
Le cycle du carbone à l’échelle des temps géologiques.
2011
2 pages; National audience
U-Pb age constraints on Carboniferous-Permian French continental basins - implications for their depositional history and correlations with European …
2022
International audience; Late Carboniferous to Permian basins of western Europe (~Gzhelian to Artinskian), developed during thelate stages of the Variscan orogeny in equatorial paleolatitudes. The stratigraphic context of most of thesebasins remains poorly constrained, because mainly based on “continental stages” (e.g., Stephanian, Autunian,Saxonian and Thuringian) that are diachronous. Therefore, correlating these basins together and withinternationally recognized stratigraphic marine stages requires precise radiochronologic ages.To the south of the Paris Basin (France), volcanic ash-fall layers (i.e., tonsteins) are interbedded in theCarboniferous-Permian sedimentary successions of the Aum…
Hirnantian glacial and deglacial record in SW Djado Basin (NE Niger).
2007
Pluridisciplinary fieldwork highlights features generated by an extended ice-sheet in the Djado Basin during the Hirnantian. Two glacial palaeovalley systems associated with glacial pavements and separated by thin glaciomarine interstadial series are revealed. Rigid glacial pavements characterised by abrasion erosion are differentiated from soft glacial pavements characterised by soft-bed deformation. Glacial pavements are associated with subglacial bedforms such as megaflutes, flutes and meltwater channels. They are also associated with clastic dykes and glaciotectonic structures such as deformed flutes, subglacial folds and duplex structures. This record demonstrates that ice was warm-bas…
Sédimentologie des cônes juxta-glacaires sous-marins.
2006
International audience