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31.
Rodrigues Karine dos Santos do Carmo Luiz Felipe Rodrigues Palmeira Ana Cristina Pinto de Almeida Andrioni Marcelo 《Natural Hazards》2022,110(3):2277-2302
Natural Hazards - After a storm displaced the P-70 platform ship located in Guanabara Bay to the coast on January 30, 2020, a numerical investigation was carried out with the BRAMS (Brazilian... 相似文献
32.
Perrine Cruaud Carole Decker Karine Olu Sophie Arnaud‐Haond Claire Papot Jocelyn Le Baut Adrien Vigneron Alexis Khripounoff Nicolas Gayet Ccile Cathalot Jean‐Claude Caprais Patricia Pignet Anne Godfroy Marie‐Anne Cambon‐Bonavita 《Marine Ecology》2019,40(3)
This study provides an analysis of vesicomyid bivalve–symbiont community distribution across cold seep and hydrothermal vent areas in the Guaymas Basin (Gulf of California, Mexico). Using a combination of morphological and molecular approaches including fluorescent in situ hybridization (FISH), and electronic microscopy observations, vesicomyid clam species and their associated symbionts were characterized and results were analyzed in light of geochemical conditions and other on‐site observations. A greater diversity of vesicomyids was found at cold seep areas, where three different species were present (Phreagena soyoae [syn. kilmeri], Archivesica gigas, and Calyptogena pacifica). In contrast, A. gigas was the only species sampled across the hydrothermal vent area. The same haplotype of A. gigas was found in both hydrothermal vent and cold seep areas, highlighting possible contemporary exchanges among neighboring vents and seeps. In either ecosystem, molecular characterization of the symbionts confirmed the specificity between symbionts and hosts and supported the hypothesis of a predominantly vertical transmission. In addition, patterns of clams could reflect potential niche preferences for each species. The occurrence of numerous traces of vesicomyid movements on sediments in the sites colonized by A. gigas seemed to indicate that this species might have a better ability to move. Furthermore, variation in gill sulfur content could reveal a higher plasticity and sulfur storage capacity in A. gigas. Thus, the distribution of vesicomyid species across the chemosynthetic areas of the Guaymas Basin could be explained by differences in biological traits of the vesicomyid species that would allow A. gigas to more easily exploit transient and punctual sources of available sulfide than P. soyoae. 相似文献
33.
Erik E. Cordes Marina R. Cunha Joëlle Galéron Camilo Mora Karine Olu-Le Roy Myriam Sibuet Saskia Van Gaever Ann Vanreusel & Lisa A. Levin 《Marine Ecology》2010,31(1):51-65
Cold seeps are among the most heterogeneous of all continental margin habitats. Abiotic sources of heterogeneity in these systems include local variability in fluid flow, geochemistry, and substrate type, which give rise to different sets of microbial communities, microbial symbiont-bearing foundation species, and associated heterotrophic species. Biogenic habitats created by microbial mats and the symbiotic species including vesicomyid clams, bathymodiolin mussels, and siboglinid tubeworms add an additional layer of complexity to seep habitats. These forms of habitat heterogeneity result in a variety of macrofaunal and meiofaunal communities that respond to changes in structural complexity, habitat geochemistry, nutrient sources, and interspecific interactions in different ways and at different scales. These responses are predicted by a set of theoretical metacommunity models, the most appropriate of which for seep systems appears to be the 'species sorting' concept, an extension of niche theory. This concept is demonstrated through predictable patterns of community assembly, succession, and beta-level diversity. These processes are described using a newly developed analytical technique examining the change in the slope of the species accumulation curve with the number of habitats examined. The diversity response to heterogeneity has a consistent form, but quantitatively changes at different seep sites around the world as the types of habitats present and the size-classes of fauna analyzed change. The increase in beta diversity across seep habitat types demonstrates that cold seeps and associated biogenic habitats are significant sources of heterogeneity on continental margins globally. 相似文献
34.
Youngseob Kim Karine Sartelet Christian Seigneur 《Journal of Atmospheric Chemistry》2009,62(2):89-119
Two recent gas-phase chemical kinetic mechanisms for tropospheric ozone formation, one based on the lumped-structure approach (CB05) and the other based on the lumped-molecule approach (RACM2), are compared for simulations of ozone over Europe. The host air quality model is POLAIR3D of the Polyphemus modeling platform. A one-month period (15 July to 15 August 2001) is simulated. Model performance is satisfactory with both mechanisms. Overall, the two mechanisms give similar results with a domain-averaged difference of 3 ppb and a mean fractional absolute difference of 5% (values averaged over the month for the daily 8-h average maximum ozone concentrations). This difference results from different treatments in the two mechanisms for both inorganic and organic chemistry. Differences in the treatment of the inorganic chemistry are due mainly to differences in the kinetics of two reactions: NO + O3 \(\longrightarrow\) NO2 + O2 and NO + HO2 \(\longrightarrow\) NO2 + OH. These differences lead to a domain-averaged difference in ozone concentration of 5%, with RACM2 kinetics being more conducive to ozone formation. Differences in the treatment of organic chemistry lead to a domain-averaged difference in ozone concentration of 3%, with CB05 chemistry being more conducive to ozone formation. This average difference results in part from compensating effects among various VOC classes and some significant differences are identified at specific locations (the coastline of northern Africa and eastern Europe: 9%) and for specific organic classes (aldehydes, biogenic alkenes and aromatics). Differences in the treatment of the organic chemistry result from various aspects. For some VOC classes, such as aldehydes and biogenic alkenes, the more detailed explicit treatments using more model species in RACM2 lead to either greater or lower reactivity depending on the assumptions made for the oxidation products. For other VOC species, such as aromatics, the assumptions made about the major chemical oxidation pathways (aromatic alcohol formation in CB05 vs. ring opening in RACM2) affect the ozone formation significantly. Reconciliation of different chemical kinetic mechanisms will require experimental data to reduce current uncertainties in the kinetic (e.g., NO oxidation) and mechanistic (e.g., aromatics oxidation) representations of major chemical pathways. 相似文献
35.
Thibaut Caley Bruno Malaizé Franck Bassinot Steven C. Clemens Nicolas Caillon Rossignol Linda Karine Charlier Helene Rebaubier 《Quaternary Research》2011,76(2):285-293
Previous studies have suggested that Marine Isotope Stage (MIS) 13, recognized as atypical in many paleoclimate records, is marked by the development of anomalously strong summer monsoons in the northern tropical areas. To test this hypothesis, we performed a multi-proxy study on three marine records from the tropical Indian Ocean in order to reconstruct and analyse changes in the summer Indian monsoon winds and precipitations during MIS 13. Our data confirm the existence of a low-salinity event during MIS 13 in the equatorial Indian Ocean but we argue that this event should not be considered as “atypical”. Taking only into account a smaller precession does not make it possible to explain such precipitation episode. However, when considering also the larger obliquity in a more complete orbitally driven monsoon “model,” one can successfully explain this event. In addition, our data suggest that intense summer monsoon winds, although not atypical in strength, prevailed during MIS 13 in the western Arabian Sea. These strong monsoon winds, transporting important moisture, together with the effect of insolation and Eurasian ice sheet, are likely one of the factors responsible for the intense monsoon precipitation signal recorded in China loess, as suggested by model simulations. 相似文献
36.
Cindy Lebeaupin Brossier Karine Béranger Charles Deltel Philippe Drobinski 《Ocean Modelling》2011,36(1-2):1-25
The Mediterranean basin features a semi-enclosed sea, where interactions and feedbacks between the atmosphere and the Sea at various temporal and spatial scales play a predominant role in the regional climate. This study analyzes the Mediterranean Sea response in sensitivity experiments conducted by driving the NEMO-MED12 oceanic model in perpetual mode with various atmospheric forcings, all produced by the WRF non-hydrostatic mesoscale atmospheric model, but differing by their resolutions: two horizontal resolutions (20 km at basin scale and 6.7 km in the North-Western [NWE] area) and two temporal resolutions (daily and three-hourly). The atmospheric fields available from August 1998 to July 1999 are in good agreement with estimates derived from satellite data. The heat budget of the Mediterranean Sea represents an heat loss of 5 W/m2 and the annual freshwater budget is ?1.04 m, in agreement with climatologies. An increase in the spatial resolution in the NWE area modifies the modeled circulation from ?10% to +15% for the SST, from ?30% to +50% for the SSS, from ?10% to +30% for the MLD and from ?10% to +30% for the EKE in surface. The increase in the wind speed with a better chanelling by the land orography enhances in particular the oceanic convection process in the NWE area. On the other hand, the increase in the temporal resolution reduces the convection process, because of the diurnal restratification of the oceanic upper layer. It also reduces the surface parameters high-frequency variability, whereas it increases the EKE values in surface, due to the rapid response to the wind. 相似文献
37.
Karine Issautier Nicole Meyer-Vernet Viviane Pierrard Joseph Lemaire 《Astrophysics and Space Science》2001,277(1-2):189-193
We use a kinetic collisionless model of the solar wind to calculate the radial variation of the electron temperature and obtain
analytical expressions at large radial distances. In order to be compared with Ulysses observations, the model, which initially
assumed a radial magnetic field, has been generalized to a spiral magnetic field. We present a preliminary comparison with
Ulysses observations in the fast solar wind at high heliospheric latitudes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
38.
Alexie Heimburger Mickael Tharaud Fabrice Monna Rémi Losno Karine Desboeufs Elisabeth B. Nguyen 《Geostandards and Geoanalytical Research》2013,37(1):77-85
The fifth version of natural river water certified reference material, SLRS‐5 (National Research Council – Conseil National de Recherches Canada), is commonly used to control the quality of major and trace element measurements. Concentrations of silicon and thirty‐one uncertified trace elements have been reported for the certified reference material SLRS‐4, but they are not yet available for SLRS‐5. Here, SLRS‐5/SLRS‐4 ratios were deduced from SLRS‐5 and SLRS‐4 measurements by inductively coupled plasma‐atomic emission spectrometry and high‐resolution inductively coupled plasma‐mass spectrometry for certified elements and thirty‐five uncertified elements (rare earth elements, B, Bi, Br, Cs, Ga, Ge, Hf, Li, Nb, P, Pd, Rb, Rh, S, Sc, Si, Sn, Th, Ti, Tl, Y). Both reference materials were measured directly one after the other, so that calculated elemental ratios would not be notably influenced either by calibration uncertainties or by eventual long‐term instrumental drift. The computed ratios are in good agreement with those deduced from the certified values. We also report concentrations for thirty‐three uncertified elements in SLRS‐5 by combining the measured SLRS‐5/SLRS‐4 ratios and the published SLRS‐4 values. The resulting new data set provides target SLRS‐5 values, which will be useful in quality control procedures. 相似文献
39.
Franois Charles Susanna Lopez-Legentil Antoine Grmare Jean Michel Amouroux Martin Desmalades Gilles Vtion Karine Escoubeyrou 《Continental Shelf Research》2005,25(19-20):2533
Environmental parameters and gross sedimentation rates (GSR) were monitored at a fixed site located in the Bay of Banyuls-sur-Mer (NW Mediterranean), between March 1997 and April 1998, together with the main biochemical characteristics of both sedimenting and sedimented particulate organic matter (POM). Three storms which occurred during this time period resulted in natural sediment resuspension. This is indicated by the corresponding increase in GSR and a decrease in the enzymatically hydrolysable amino acids/totally hydrolysable amino acids ratio (EHAA/THAA), within the sedimenting POM. Only the strongest storm resulted in (1) a transitory increase in fine-grained particles, (2) concomitant increases in organic carbon, carbohydrates, lipids and THAA, and (3) a decrease in the EHAA/THAA ratio in surficial sediments. For most of the assayed parameters, the values recorded after the December 1997 storm corresponded to extremes for the whole period under study. This emphasises the role of storms in controlling the characteristics of sedimented and sedimenting POM.Ten sediment types, with contrasting biochemical characteristics, were selected for experiments; these were based on the results of the monitoring survey and were used during adsorption and absorption experiments involving 14C tetrachlorobiphenyl (TCB). Adsorption rates differed significantly between the sediment types, but did not correlate with any of the assayed biochemical parameters. Absorption efficiency by the mussel Mytilus galloprovincialis also differed between the sediment types; it correlated positively with all the assayed biochemical parameters, except lipids. Comparison between the magnitudes of the increase in GSR, together with the decrease in absorption efficiency during resuspension events, suggests that resuspension tends to enhance the transfer of organic pollutants in the benthic food chain. 相似文献
40.