A5102966750- Geology and Paleoclimatology Research
- Silicon Effects in Agriculture
- Isotope Analysis in Ecology
- Archaeology and ancient environmental studies
- Marine and coastal ecosystems
- Geological formations and processes
- Geological and Geophysical Studies Worldwide
- Geochemistry and Elemental Analysis
- Marine Biology and Ecology Research
- Analytical chemistry methods development
- Archaeological and Geological Studies
- Geomagnetism and Paleomagnetism Studies
- Mass Spectrometry Techniques and Applications
- Analytical Chemistry and Chromatography
- Marine and coastal plant biology
- Hydrology and Watershed Management Studies
- Climate variability and models
- Nuclear Physics and Applications
- Diatoms and Algae Research
- Transboundary Water Resource Management
- Pleistocene-Era Hominins and Archaeology
- Environmental and Agricultural Sciences
- Landslides and related hazards
- Radioactive contamination and transfer
- Karst Systems and Hydrogeology
Centre de Recherche et d’Enseignement de Géosciences de l’Environnement
2007-2024
Aix-Marseille Université
2008-2024
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2023-2024
Institut de Recherche pour le Développement
2018-2024
Centre National de la Recherche Scientifique
2007-2024
Sustainable Europe Research Institute
2017-2021
Collège de France
2018-2019
University of Wollongong
2017
Abstract. BIOSOPE cruise covered an oceanographic transect through the centre of South Pacific Gyre (SPG) from Marquesas archipelago to Peru-Chile upwelling (PCU). Water samples 6 depths in euphotic zone were collected at 20 stations. The concentrations suspended calcite particles, coccolithophores cells and detached coccoliths estimated together with size weight using automatic polarizing microscope, a digital camera, collection softwares performing morphometry pattern recognition. Some...
Rationale The precision obtained in routine isotope analysis of water (δ 17 O, δ 18 2 H, O‐excess and d‐excess values) using cavity ring‐down spectroscopy is usually below the instrument specifications provided by manufacturer. This study aimed at reducing this discrepancy, with particular attention paid to mitigating memory effect (ME). Methods We used a Picarro L2140i analyzer coupled high‐precision A0211 vaporizer an A0325 autosampler. magnitude duration ME were estimated 24 series 50...
Quantitative data are needed to constrain vegetation-hydroclimate in water cycle modelling. Here, we use the triple oxygen isotope composition (δ'18O and 17O-excess) of compartments track transfers mixing within soil-plant-atmosphere continuum. At three AMMA-CATCH sites Benin Senegal monitored δ'18O 17O-excess precipitation, groundwater, soil plant water, as well phytoliths, an indicator atmospheric relative humidity. We found that : 1) precipitation is very stable over...
Abstract. Continental atmospheric relative humidity (RH) is a key climate parameter. Combined with temperature, it allows us to estimate the concentration of water vapor, which one main components global cycle and most important gas contributing natural greenhouse effect. However, there lack proxies suitable for reconstructing, in quantitative way, past changes continental humidity. This reduces possibility making model–data comparisons necessary implementation models. Over 10 years,...
Abstract. In the Mediterranean area, 4.2 ka BP event is recorded with contrasting expressions between regions. southern Alps, high-altitude Lake Petit (Mercantour Massif, France; 2200 m a.s.l.) offers pollen and diatom-rich sediments covering last 4800 years. A multi-proxy analysis recently revealed a detrital pulse around 4200 cal due to increasing erosion in lake catchment. The involvement of rapid climate change leading runoff soil was proposed. Here, order clarify this hypothesis, we...
Abstract. Continental relative humidity (RH) is a key climate parameter, but there lack of quantitative RH proxies suitable for model–data comparisons. Recently, combination chamber and natural transect calibrations have laid the groundwork examining robustness triple oxygen isotope composition (δ′18O 17O-excess) phytoliths, that can preserve in sediments, as new proxy past changes RH. However, it was recommended besides RH, additional factors may impact δ′18O 17O-excess plant water...
Abstract. Oxygen isotopes in biogenic silica (δ18OBSi) from lake sediments allow for quantitative reconstruction of past hydroclimate and proxy-model comparison terrestrial environments. The signals individual records have been attributed to different factors, such as air temperature (Tair), atmospheric circulation patterns, hydrological changes, evaporation. While every has its own local set drivers δ18O variability, here we explore the extent which regional or even global emerge a series...
Abstract. Continental atmospheric relative humidity is a major climate parameter whose variability poorly understood by global models. Models' improvement relies on model–data comparisons for past periods. However, there are no truly quantitative indicators of the pre-instrumental period. Previous studies highlighted relationship between triple oxygen isotope composition phytoliths, particularly 17O excess and humidity. Here, as part series calibrations, we examine respective controls soil...
Abstract. BIOSOPE cruise achieved an oceanographic transect from the Marquise Islands to Peru-Chili upwelling (PCU) via centre of South Pacific Gyre (SPG). Water samples 6 depths in euphotic zone were collected at 20 stations. The concentrations suspended calcite particles, coccolithophores cells and detached coccoliths estimated together with size weight using automatic polarizing microscope, a digital camera, collection softwares performing morphometry pattern recognition. Some these are...
Abstract. Continental relative humidity (RH) is a key-climate parameter. However, there lack of quantitative RH proxies suitable for climate model-data comparisons. Recently, combination chamber and natural transect calibrations laid the groundwork examining robustness triple oxygen isotope composition (δ18O, δ17O) phytoliths as new proxy past changes in RH. it was recommended that besides RH, additional factors may impact δ18O δ17O plant water be examined. Here, effects leaf anatomy,...
Abstract. Continental atmospheric relative humidity (RH) is a key climate-parameter. Combined with temperature, it allows us to estimate the concentration of water vapor which one main components global cycle and most important gas contributing natural greenhouse effect. However, there lack proxies suitable for reconstructing, in quantitative way, past changes continental humidity. This reduces possibility make model-data comparisons necessary implementation climate models. Over 10 years,...
Abstract. Oxygen isotopes in biogenic silica (δ18OBSi) from lake sediments allow for quantitative reconstruction of past hydroclimate and proxy–model comparison terrestrial environments. The signals individual records have been attributed to different factors, such as air temperature (Tair), atmospheric circulation patterns, hydrological changes evaporation. While every will its own set drivers d18O, here we explore the extent which regional or even global emerge a series palaeoenvironmental...
measured d 18 O, 17 O and O-excess of irrigation water (IW), soil water, leaf (LW) phytoliths.
Abstract. The 4.2 kyrs event, used as a marker of holocene stratigraphy, has been described rapid climate change in the northern hemisphere triggering droughts Mediterranean region. However, severity and geographical extent this event are still subject investigation considering small number palaeoclimatic records for time period, presence contrasted climatic expressions between areas. At Petit Lake (France, Alps, 2200 m a.s.l) multiproxy study Holocene lake sediments revealed major changes...
<p>The oxygen isotope signature of leaf water is used to trace several processes at the soil-plant-atmosphere interface. During photosynthesis, it transferred atmospheric CO<sub>2</sub> and O<sub>2</sub>, which can be for reconstructing past changes in gross primary production. The additionally imprints organic mineral compounds, such as phytoliths, paleoclimate paleovegetation proxies when extracted from sedimentary...
<p>Recent studies showed that the <sup>17</sup>O-excess of plant leaf biogenic silicates (phytoliths) can be used to quantify atmospheric relative humidity occurring during water transpiration. The vs ∂<sup>18</sup>O signature phytoliths also trace back water. In a similar way, lacustrine diatoms is expected record lake in which they formed. Therefore, triple oxygen isotope composition extracted from...
<p>This study aims at evaluating the information carried by <sup>17</sup>O-excess composition of precipitation in sub-humid part West Africa. Located southern border Sahelian band, so-called “Sudanian Climatic Zone”, characterized annual 1200-1400mm, plays a crucial role providing water to large African watersheds such as Niger river’s one, and Lake Chad catchment. Surface-atmosphere interactions were shown...