Search results for "Global changes"
showing 10 items of 533 documents
Preface: Emerging trends in aquatic ecology III
2020
Humans have never faced such major threats to their homes as they are experiencing now. Despite several global initiatives to ameliorate environmental problems, to preserve biodiversity and to alleviate poverty, these major threats are far from being resolved. According to a recent survey conducted by Ripple et al. (2017) and signed by 15,364 scientists of 184 countries, several indicators of environmental health are still worsening significantly. For example, along with the continuing increase of atmospheric CO2 and global temperatures (the threats best known by the general public as ‘‘climate change’’), there are still steep increases in atmospheric concentrations of methane and nitrous o…
Pluviométrie et circulation atmosphérique simulées par le modèle régional WRF en Afrique australe : sensibilité à la physique et variabilité interne
2011
This study evaluates the capability of the regional climate model WRF to simulate Southern African rainfall and associated atmospheric circulation, particularly over South Africa, a country covered by a dense network of in situ observations. Three sets of simulations are performed at a 35km horizontal resolution during the core of the austral rainy season (December to February: DJF) with 6-hourly forcings provided by ERA40 reanalysis. The first set quantifies sensitivity of the simulated climate to the parameterizations of atmospheric convection, planetary boundary layer and microphysics. The retained case study (DJF 1993-1994: DJF94) is representative of the South African rainfall climatol…
Le traçage isotopique pour étudier la production par les microorganismes du sol d'oxyde nitreux, gaz à effet de serre.
2008
Domaine SCIENCES DE L’ALIMENT ET AGRO-ENVIRONNEMENT
Experimental Crystallization of a High-K Arc Basalt: the Golden Pumice, Stromboli Volcano (Italy)
2006
International audience; The near-liquidus crystallization of a high-K basalt (PST-9 golden pumice, 49·4 wt % SiO2, 1·85 wt % K2O, 7·96 wt % MgO) from the present-day activity of Stromboli (Aeolian Islands, Italy) has been experimentally investigated between 1050 and 1175°C, at pressures from 50 to 400 MPa, for melt H2O concentrations between 1·2 and 5·5 wt % and {Delta}NNO ranging from –0·07 to +2·32. A drop-quench device was systematically used. AuPd alloys were used as containers in most cases, resulting in an average Fe loss of 13% for the 34 charges studied. Major crystallizing phases include clinopyroxene, olivine and plagioclase. Fe–Ti oxide was encountered in a few charges. Clinopyro…
CAROLS campaigns 2009: First Results
2010
International audience; The CAROLS, L band radiometer, is built and designed as a copy of EMIRAD II radiometer of DTU team. It is a Correlation radiometer with direct sampling and fully polarimetric (i.e 4 Stockes). It will be used in conjunction with other airborne instruments (in particular the C-Band scatterometer (STORM) and IEEEC GPS system, Infrared CIMEL radiometer and one visible camera), in coordination with in situ field campaigns for SMOS CAL/VAL. The instruments are implemented on board the French research airplane ATR42. A scientific campaign with thirteen flights is realized over south-western France, Valencia site and Bay of Biscay (Atlantic Ocean) in spring 2009. In order to…
Evolution du bilan hydrique à l'échelle de bassins versants en contexte de changement climatique - Mise place d’une méthodologie.
2014
6 pages; International audience
Le changement climatique : où en sommes-nous ?
2018
Greenhouse gases (GHGs), naturally part of the atmosphere, have protected us from severe glaciations in the past. Today, human activities increase GHG concentrations and cause rapid and unprecedented Earth warming. Climate change is not resume only to warming, water cycle is also changed. All the research confirms: the climate is changing fast, too fast for ecosystems and societies to adapt. Despite the alerts of the international scientific community, States gathered into Conferences of the Parties (COP) ratify agreements but do not comply with all their commitments. Public opinion polls indicate that climate change is perceived as a risk, but jobs and taxes override environmental concerns…
Les terres cuites architecturales comme sources d'information chronologique et technique des édifices avant l'an mil
2008
A partir de l'étude d'un édifice phare de l'Ouest de la France (Église Notre-Dame sous Terre au Mont-Saint-Michel) mous montrons comment le couplage des études de bâti permettant l'identification d'ensembles maçonnés et leur chronologie relative, avec les méthodes de datation des terres cuites par thermoluminescence et archéomagnétisme, et des charbons de mortier par radiocarbone, aboutit à des informations particulièrement novatrices sur la chronologie de la production des briques, leur éventuel remploi ou sur leur production ad nove, mais aussi, plus inattendu, sur des éléments technologiques de leur production. Les orientations actuelles des recherches méthodologiques pour la datation ph…
'Dark Ecological Network': strategically tackling light pollution for biodiversity and people
2021
Night-time light pollution from artificial sources can disrupt biological processes and fragment habitats. This study presents a new concept foraddressing the problem: a 'dark ecological network'. Its development involves mapping a new system of connected functional zones and corridors where dark can be preserved to help birds, bats and other taxa, and gives people the chance to experience starry skies.
Lien entre démarrage de la saison des pluies et rendements agricoles observés/simulés du mil sur le site AMMA-CATCH.
2011
International audience