Weak lensing predictions at intermediate scales     

Ludovic Van Waerbeke  Takashi Hamana  †  Román Scoccimarro  Stephane Colombi  Francis Bernardeau 《Monthly notices of the Royal Astronomical Society》2001,322(4):918-926

As pointed out in previous studies, the measurement of the skewness of the convergence field κ will be useful in breaking the degeneracy among the cosmological parameters constrained from weak lensing observations. The combination of shot noise and finite survey volume implies that such a measurement is likely to be performed in a range of intermediate scales (0.5 to 20 arcmin) where neither perturbation theory nor the hierarchical ansatz applies. Here we explore the behaviour of the skewness of κ at these intermediate scales, based on results for the non-linear evolution of the mass bispectrum. We combined different ray-tracing simulations to test our predictions, and we find that our calculations describe accurately the transition from the weakly non-linear to the strongly non-linear regime. We show that the single lens-plane approximation remains accurate even in the non-linear regime, and we explicitly calculate the corrections to this approximation. We also discuss the prospects of measuring the skewness in upcoming weak lensing surveys.  相似文献   

Biological evidence of sea-level rise during the last 4500 years on the rocky coasts of continental southwestern France and Corsica     

Jacques Laborel  Christophe Morhange  Raymond Lafont  Joë  l Le Campion  Fran  oise Laborel-Deguen  Stephane Sartoretto 《Marine Geology》1994,120(3-4):203-223

On the rocky coasts of the northwestern Mediterranean basin, biogenic littoral rims built by the coralline rhodophyte Lithophyllum lichenoides develop, whose remains may be preserved for millennia when submerged in a rising sea environment. These remains can be used as biological indicators of recent sea-level variations. Our survey of the continental coasts of Var and Bouches du Rhône, west of Marseilles (southern France) and of northern Corsica shows that relative sea level rose about 1.6 m in the study area during the last 4500 years without exceeding the present datum. The rate of sea-level rise was 0.4 mm per year between 4500 and 1500 yr B.P. and slowed down to 0.2 mm per year from 1500 yr B.P. to present time. There are also morphological indications of an acceleration of the rate of sea-level rise during the last century, supporting the evidence of tide gauges. Regions at the periphery of the above zone (Alpes Maritimes, Italian border zone, and the French and Spanish Catalonia regions) were also surveyed, but a weaker development of Lithophyllum rims and bad preservation of algal remains led to unconvincing dates which could also be linked to regional tectonic trends.  相似文献   

Reconciling theoretical versus empirical target strengths of krill: effects of phase variability on the distorted-wave Born approximation   总被引：3，自引：5，他引：3  

Demer  David A.; Conti  Stephane G. 《ICES Journal of Marine Science》2003,60(2):429-434

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Improved parameterization of the SDWBA for estimating krill target strength   总被引：4，自引：0，他引：4  

Conti  Stephane G.; Demer  David A. 《ICES Journal of Marine Science》2006,63(5):928-935

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Seafloor mapping from high-density satellite altimetry     

Nicolas Baudry  Stephane Calmant 《Marine Geophysical Researches》1996,18(2-4):135-146

In this paper, we publish the results of a bathymetry survey based on the processing of satellite altimetry data. Data gathered from GEOSAT (Geodetic Mission), SEASAT, ERS-1 and TOPEX/POSEIDON satellites were processed to recover the seafloor topography over new seamounts in a test area located in the south central Pacific. We show that by processing high-density satellite altimetry data, alone or in combination with shiptrack bathymetric data, it is possible to produce full coverage bathymetric maps.  相似文献   

Haar wavelets as a tool for the statistical characterization of variability     

Ryan Price  Stephane Vincent  Stephan LeBohec   《Astroparticle Physics》2011,34(12):871-877

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Speleothem evidence of warm episodes in northeast France during Marine Oxygen Isotope Stage 3 and implications for permafrost distribution in northern Europe     

Edwige Pons-Branchu  Bruno Hamelin  Stephane Jaillet 《Quaternary Research》2010,74(2):246-251

U-Th ages have been obtained by TIMS on the growth periods of a stalagmite from the “Grotte des Puits de Pierre-la-Treiche” (northeastern France), during the middle part of the “Weichselian glaciation” (Marine Isotope Stage 3), between 55.36 ± 0.95 and 53.34 ± 0.49 ka and around 45.85 ± 0.49 ka. These episodes are contemporaneous with abrupt climatic variations recorded in Greenland ice cores (Greenland interstadials 12, 14 and 15) that have been previously recognized in European speleothems. They also coincide with two interstadials, known as “Goulotte” and “Pile” in the Grande Pile pollen sequence (eastern France), which have been correlated with the Moershoofd complex in the Netherlands. Such evidence of speleothem deposition related to temperate episodes gives a strong indication of the absence of continuous shallow permafrost during the middle part of MIS 3 in northeastern France.  相似文献   

Effects of nitrogen and sulphide on macroinfaunal community: a microcosm study     

Shin PK  Cheung CK  Cheung SG 《Marine pollution bulletin》2006,52(11):1333-1339

A microcosm experiment was conducted to test the short-term effects of nitrogen (as TKN, total Kjeldahl nitrogen) and sulphide (as AVS, acid volatile sulphide) on macrobenthic infauna over a period of 8 weeks. The experiment consisted of four treatments using sediment cores (D: 8 cm, H: 20 cm) with addition of: I, nitrogen (N) to an in situ mean level of 0.48 mg Ng(-1) dw; II, sulphidic solution (S) to an in situ mean level of 318.8 microM S g(-1) dw; III, nitrogen and sulphidic solution (NS) to in situ mean levels of 0.45 mg Ng(-1) dw and 329.0 microM S g(-1) dw, respectively, and IV, control with no addition of N and S. Sediment cores were retrieved for analysis of infaunal composition after weeks 2, 4 and 8. A total of 646 specimens of macrobenthic infauna belonging to 27 species were recorded from the cores, in which polychaetes were the most abundant with respect to species and individual numbers. Mean species number and diversity H' of the control and N treatment was statistically higher than S and NS treatments, mean individual number of the S treatment was larger than the NS treatment, and mean evenness J of the S treatment was lower than the N and NS treatments as well as the control. Individual numbers also showed a significant increase from weeks 2 to 8, whereas evenness J decreased in weeks 4 and 8. Multivariate analyses of the faunal data suggested that benthic composition of the N treatment and control did not differ during the experimental period, but changes in benthic structure in S and NS treatments were evident. The present findings demonstrated the dose-response relationship of benthic species changes under controlled addition of N and S. The response to N and S additions in the sediment microcosms was in agreement with the general effects of organic enrichment on macrobenthic communities along a spatial gradient of organic pollution as described by Pearson and Rosenberg [Pearson, T.H., Rosenberg, R., 1978. Macrobenthic succession in relation to organic enrichment and pollution of the marine environment. Oceanography and Marine Biology Annual Review 16, 229-311]. However, in the present experiment, community changes in the treatments were observable in a short, temporal scale.  相似文献   

Baseline data of subtropical coral communities in Hoi Ha Wan Marine Park, Hong Kong, obtained by an underwater remote operated vehicle (ROV)     

Lam K  Shin PK  Bradbeer R  Ku KK  Hodgson P  Cheung SG 《Marine pollution bulletin》2007,54(1):107-112

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Experimental analysis of groundwater flow through a landslide slip surface using natural and artificial water chemical tracers     

Stephane Binet  Herve Jomard  Thomas Lebourg  Yves Guglielmi  Emmanuel Tric  Catherine Bertrand  Jacques Mudry 《水文研究》2007,21(25):3463-3472

Artificial and natural tracer tests combined with high accurate electronic distancemeter measurements are conducted on a small landslide with a well known slip surface geometry. Outflow yields and chemical contents are monitored for all the experiment duration and they analyzed to estimate the slip surface hydraulic parameters. The main result is that the slip surface acts as a drain for groundwater flows that evacuates interstitial pressures in the slope and brings the sliding mass to be more stable one. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献