Search results for "CLIMAT"
showing 10 items of 5990 documents
SST Comparison of AVHRR and MODIS Time Series in the Western Mediterranean Sea
2020
La temperatura de la superficie del mar (SST) es un parámetro clave para comprender los procesos atmosféricos y oceánicos. Desde finales de la década de 1980, las imágenes de satélite infrarrojas se han utilizado para complementar los registros in situ para estudiar la variabilidad temporal y espacial de la SST. El radiómetro avanzado de muy alta resolución (AVHRR) del satélite de la Administración Nacional Oceánica y Atmosférica (NOAA) fue el primer sensor utilizado con éxito para calcular la SST después del desarrollo y validación del algoritmo de corrección atmosférica conocido como 'ventana dividida'. Más recientemente, el espectrorradiómetro de imágenes de resolución MODERADA (MODIS) a…
On Line Validation Exercise (OLIVE): A Web Based Service for the Validation of Medium Resolution Land Products. Application to FAPAR Products
2014
International audience; The OLIVE (On Line Interactive Validation Exercise) platform is dedicated to the validation of global biophysical products such as LAI (Leaf Area Index) and FAPAR (Fraction of Absorbed Photosynthetically Active Radiation). It was developed under the framework of the CEOS (Committee on Earth Observation Satellites) Land Product Validation (LPV) sub-group. OLIVE has three main objectives: (i) to provide a consistent and centralized information on the definition of the biophysical variables, as well as a description of the main available products and their performances (ii) to provide transparency and traceability by an online validation procedure compliant with the CEO…
Inferring Phytoplankton, Terrestrial Plant and Bacteria Bulk δ¹³C Values from Compound Specific Analyses of Lipids and Fatty Acids.
2015
Stable isotope mixing models in aquatic ecology require δ13C values for food web end members such as phytoplankton and bacteria, however it is rarely possible to measure these directly. Hence there is a critical need for improved methods for estimating the δ13C ratios of phytoplankton, bacteria and terrestrial detritus from within mixed seston. We determined the δ13C values of lipids, phospholipids and biomarker fatty acids and used these to calculate isotopic differences compared to the whole-cell δ13C values for eight phytoplankton classes, five bacterial taxa, and three types of terrestrial organic matter (two trees and one grass). The lipid content was higher amongst the phytoplankton (…
Revegetation through hydroseeding in degraded Mediterranean areas
2012
Hydroseeding is a technique increasingly used to establish vegetation on degraded areas in order to perform environmental protection. The objective of this paper was to evaluate the effectiveness of four different hydroseeding methods on a degraded artificial slope in the southern Mediterranean area determining total vegetation cover, hydroseeding vegetation cover, hydroseeding success index (HSI), natural and hydroseeded vegetation height. The test area does not allow the use of any operating machine for soil and vegetation management, the only applicable technique is therefore hydroseeding. After hydroseeding was applied (December 2010), 21 checks were carried out every 15 days (from Janu…
Regional metacommunities in two coastal systems: spatial structure and drivers of plant assemblages
2014
Aim Biogeographical patterns in metacommunities are still poorly understood, and different processes are expected to occur in different habitats. We analysed the regional plant metacommunities of coastal habitats to test whether (1) the influence of space and climate differs between two habitats differentiated along the seashore–inland gradient, and (2) regional variation in species composition of these habitats can be ascribed to different metacommunity paradigms. Location The entire coast of the Iberian Peninsula, south-western Europe. Methods We collected data on the plant species composition of coastal sites on sand dunes across 3000 km of coastline. The sites were classified into two h…
Holocene sea level change in Malta
2013
A multidisciplinary approach has been applied to study sea level changes along the coast of Malta using data collected from underwater archaeological remains. The elevation of archaeological markers have been compared with predicted sea level curves providing new bodies of evidence that outline the vertical tectonic behaviour of this region, allowing estimation of the relative sea level changes that occurred in this area of the Mediterranean since the Bronze Age. During the Roman Age, sea level was at −1.36 ± 0.1 m, while in the Midde Age it was at −0.56 ± 0.2 m, in agreement with previous estimations for the Mediterranean region. Data indicate that Malta was tectonically stable during the …
Un clos…. ou des clos ? Quelques réflexions autour d'une pratique de démarcation en Côte de Nuits et Côte de Beaune
2018
In Burgundy, the enclosure is strongly linked to the viticulture. Nevertheless, its meaning, its origin and its history remain quite unknown. This paper proposes a survey in medieval and modern sources in order to question the chronology of the practice and its value (or values) on the Côte de Nuits and the Côte de Beaune. On the Burgundian hillside, the rhythm of enclosure appearances is discontinuous: it is marked by two major peaks, one at the turn of the 12th and 13th centuries, the other between the 19th and 20th centuries. Their value, their role or their symbolic potential differ a lot, although their shape and location in the landscape may be unchanged. For the Middle Ages, the hist…
Le vignoble français face au changement climatique : l'élaboration d’une stratégie d’adaptation à partir de scénarios de prospective
2021
National audience