Estimating Sensible and Latent Heat Fluxes over an Inland Water Body Using Optical and Microwave Scintillometers     

Pierre  Adrien  Isabelle  Pierre-Erik  Nadeau  Daniel F.  Thiboult  Antoine  Perelet  Alexei  Rousseau  Alain N.  Anctil  François  Deschamps  Jaril 《Boundary-Layer Meteorology》2022,185(2):277-308

Boundary-Layer Meteorology - Observations of turbulent heat fluxes over inland water bodies are scarce despite being critical to adequate lake parametrization for numerical weather forecast and...  相似文献   

A new assemblage of ray-finned fishes (Teleostei) from the Lower Oligocene “Schistes à Meletta” from the Glières plateau, Bornes Massif, eastern France     

Antoine Pictet  Jérôme Chablais  Lionel Cavin 《Swiss Journal of Geoscience》2013,106(2):279-289

A recently discovered fish assemblage from the “Schistes à Meletta” facies (Lower Oligocene) of the Glières Plateau, Bornes Massif, Haute–Savoie, eastern France is described. The assemblage, comprising specimens ranging from fully-articulated skeletons to isolated scattered ossifications, is composed of Anenchelum cf. glarisianum, Pristigenys sp., Fistularia sp., Caranx cf. glarisianus alongside indeterminate teleosts. This new assemblage greatly increases the fish diversity previously known from the “Schistes à Meletta” of this area. The fauna shows biogeographic affinities with assemblages from the Peritethys domain, in particular from the Helvetic molassic basin and from the Paratethys. The genera identified at the Glières locality are represented today by species living in tropical nearshore environments together with species from the open sea. A possible explanation is that the environment of deposition was rather deep, and that shallow-water fishes were brought in by turbidity currents.  相似文献   

Monitoring the evolution of irrigated areas with Landsat images using backward and forward change detection analysis in the Kou watershed,Burkina Faso     

Farid Traoré  Yves Cornet  Antoine Denis  Joost Wellens  Bernard Tychon 《国际地球制图》2013,28(8):733-752

The Kou watershed is characterized by important water resources used for drinking, agriculture (especially in the irrigated areas), industry and the preservation of aquatic fauna and flora. For several decades, there has been increasing pressure on the Kou's water resources, partly because of the expansion of the irrigated agricultural areas. This study was conducted to examine this issue, focusing on one specific irrigated area. In order to monitor the expansion of irrigated areas in developing countries, a low-cost remote sensing method based on Landsat images and aerial photographs was developed. The method is based on maximum-likelihood classification, followed by backward and forward change detection analysis requiring agronomic expertise. Using pixel trajectory analysis, the method connects all pixels to their consecutive states in order to correct their current states. The study showed that the irrigated area has expanded by almost 70% over 20 years, with most of this expansion occurring in the past 10 years. The method, if validated, could be used to obtain better information on past occupation in the rural irrigated areas for which there is currently no archived data, making temporal analyses impossible.  相似文献   

北半球白垩纪-古近纪之交生物灭绝期孢粉地层学     

Antoine BERCOVICI  Vivi VAJDA  Arthur SWEET 《地层学杂志》2012,(2):165-178

长期以来,科学家们对白垩纪-古近纪(K-Pg)之交陆地上生物大灭绝事件的趋势与灭绝速率争论不断。这些争论主要集中在脊椎动物上,尤其是非鸟恐龙。尽管如此,在理解K-Pg之交的生物响应以及相关的生态系统扰动时,植被的演化也是一个重要的组成部分。本文综述北半球内白垩纪晚期至古近纪Aquilapollenites古孢粉地理大区的孢粉地层学:在美国,晚白垩世生物组合以一系列关键门类的出现为标志,其中三冬期—坎潘期过渡期以Aquilapollenites以及相关的三突起型属的出现为标志,而马斯特里赫特阶的底界以睛形型的Wodehouseia属与Kurtzipitessp.的出现为标志;Wodehouseia spinata生物组合带以较大的个体与复杂的壁构造为特征,其中一系列的被子植物孢粉单元在K-Pg之交的记录中消失了,这使得K-Pg灭绝事件容易识别;具孔类花粉和Momipites与Caryapollenites两个属的关键种的出现,标志着古近纪孢粉植物群的复苏。近期的资料涵盖了北美大陆的大部分记录,而中国、欧洲和南半球的更多研究将更有助于理解全球陆地生物圈对K-Pg之交撞击事件的响应。  相似文献   

Blocky regularization schemes for Full‐Waveform Inversion★     

Antoine Guitton 《Geophysical Prospecting》2012,60(5):870-884

With ill‐posed inverse problems such as Full‐Waveform Inversion, regularization schemes are needed to constrain the solution. Whereas many regularization schemes end up smoothing the model, an undesirable effect with FWI where high‐resolution maps are sought, blocky regularization does not: it identifies and preserves strong velocity contrasts leading to step‐like functions. These models might be needed for imaging with wave‐equation based techniques such as Reverse Time Migration or for reservoir characterization. Enforcing blockiness in the model space amounts to enforcing a sparse representation of discontinuities in the model. Sparseness can be obtained using the ?¹ norm or Cauchy function which are related to long‐tailed probability density functions. Detecting these discontinuities with vertical and horizontal gradient operators helps constraining the model in both directions. Blocky regularization can also help recovering higher wavenumbers that the data used for inversion would allow, thus helping controlling the cost of FWI. While the Cauchy function yields blockier models, both ?¹ and Cauchy attenuate illumination and inversion artifacts.  相似文献   

Mud bank colonization by opportunistic mangroves: A case study from French Guiana using lidar data     

Christophe Proisy  Nicolas Gratiot  Edward J. Anthony  Antoine Gardel  François Fromard  Patrick Heuret 《Continental Shelf Research》2009

Mud bank colonization by mangroves on the Amazon-influenced coast of French Guiana was studied using light detection and ranging (lidar) data which provide unique information on canopy geometry an sub-canopy topography. The role of topography was assessed through analysis of vegetation characteristics derived from these data. Measurements and analyses of mangrove expansion rates over space and time led to the identification of two distinct colonization processes. The first involves regular step-by-step mangrove expansion to the northwest of the experimental site. The second is qualified as ‘opportunistic’ since it involves a clear relationship between specific ecological characteristics of pioneer Avicennia and mud cracks affecting the mud bank surface and for which probabilities of occurrence were computed from terrain elevations. It is argued from an original analysis of the latter relationship that mud cracks cannot be solely viewed as water stress features that reflect desiccation potentially harmful to plant growth. Indeed, our results tend to demonstrate that they significantly enhance the propensity for mangroves to anchor and take root, thus leading to the colonization of tens of hectares in a few days. The limits and potential of lidar data are discussed with reference to the study of muddy coasts. Finally, the findings of the study are reconsidered within the context of a better understanding of both topography and vegetation characteristics on mangrove-fringed muddy coasts.  相似文献   

Late Permian to Middle Triassic correlations and palaeogeographical reconstructions in south-western European basins: New sedimentological data from Minorca (Balearic Islands, Spain)     

Bastien Linol  Antoine Bercovici  Sylvie Bourquin  Jos Bienvenido Diez  Jos Lpez-Gmez  Jean Broutin  Marc Durand  Uxue Villanueva-Amadoz 《Sedimentary Geology》2009,220(1-2):77-94

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Ricker‐compliant deconvolution          下载免费PDF全文

Jon Claerbout  Antoine Guitton 《Geophysical Prospecting》2015,63(3):615-625

Ricker‐compliant deconvolution spikes at the center lobe of the Ricker wavelet. It enables deconvolution to preserve and enhance seismogram polarities. Expressing the phase spectrum as a function of lag, it works by suppressing the phase at small lags. A by‐product of this decon is a pseudo‐unitary (very clean) debubble filter where bubbles are lifted off the data while onset waveforms (usually Ricker) are untouched.  相似文献   

Multiple-point geostatistical simulation using enriched pattern databases     

Rezaee  Hassan  Marcotte  Denis  Tahmasebi  Pejman  Saucier  Antoine 《Stochastic Environmental Research and Risk Assessment (SERRA)》2015,29(3):893-913

Stochastic Environmental Research and Risk Assessment - This study presents a new approach of generating a set of alternative training images (ATI) to use in patch-based multiple-point simulation....  相似文献   

Does Manila clam cultivation affect habitats of the engineer species Lanice conchilega (Pallas, 1766)?     

Toupoint N  Godet L  Fournier J  Retière C  Olivier F 《Marine pollution bulletin》2008,56(8):1429-1438

The major French site of Manila clam Ruditapes philippinarum (Adams and Reeves, 1850) cultivation is located in the Chausey Archipelago where the associated practices are highly mechanized: every steps of production are made with tractor-driven machinery. The Manila clam concessions are concentrated on Lanice conchilega (Pallas, 1766) bioherms, which are known to increase alpha-diversity and to locally modify sediment dynamics. This study focus on the impacts of Manila clam cultivation on (i) the natural populations of L. conchilega and on (ii) the structure of the associated benthic assemblages during the different steps of the farming production cycle. We found that the L. conchilega populations are significantly affected within the concessions where their total abundances drastically decrease, their spatial patterns are modified and the associated benthic assemblages are significantly altered. Our results are discussed in a context of a sustainable management of the Manila clam cultivation in coastal areas.  相似文献