Hydrodynamic time parameters response to meteorological and physical forcings: toward a stagnation risk assessment device in coastal areas     

Drouzy  Marion  Douillet  Pascal  Fernandez  Jean-Michel  Pinazo  Christel 《Ocean Dynamics》2019,69(8):967-987

Ocean Dynamics - Identifying zones of stagnation and deposition of terrigenous matter or contaminants induced by human activity is a key issue in coastal areas. In this paper, circulation processes...  相似文献   

Bias in hydraulic head measurements from multilevel vibrating-wire piezometers with excessively permeable backfill     

Young  Nathan L.  Lemieux  Jean-Michel  Locat  Pascal  Demers  Denis  Delottier  Hugo  Mony  Laura 《Hydrogeology Journal》2022,30(4):1337-1344

Hydrogeology Journal - An extensive network of multilevel vibrating-wire piezometers (VWP) was recently created to monitor the spatial and temporal variation of pore pressure (and hydraulic head)...  相似文献   

Definition of the Spatial Propagator and Implications for Magnetic Field Properties     

Edmondson  Justin K.  Démoulin  Pascal 《Solar physics》2019,294(6):1-22

Solar Physics - We study a quiet-Sun blowout jet which was observed on 2014 May 16 by the instruments on board the Solar Dynamics Observatory (SDO). We find the twin CME as jet-like and bubble-like...  相似文献   

Quantitative prediction of discrete element models on complex loading paths     

Luc Sibille  Pascal Villard  Félix Darve  Rodaina Aboul Hosn 《国际地质力学数值与分析法杂志》2019,43(5):858-887

The ability of discrete element models to describe quantitatively (and not only qualitatively) the constitutive behaviour of a dense sand is assessed in this paper. Two kinds of 3D discrete models are considered. Both consider spheres as elementary particles. Nevertheless, the first model implements a contact law with rolling resistance whereas the second takes into account clumps made of two spheres. The discrete models are calibrated and validated from mechanical tests performed on a dense Hostun sand with a true triaxial apparatus. The calibration is carried out from axisymmetric drained compression tests, while the validation is discussed from monotonic and cyclic stress proportional loading paths and from a circular stress path in the deviatoric stress plane. The quality of the predictions of the discrete models are evaluated by comparison with the predictions given with advanced phenomenological constitutive relations, mainly an incrementally non-linear relation. Predictions given by the discrete models are remarkable, particularly when it is put in perspective with respect to the very few number of mechanical tests required for their calibration. However, these results and conclusions were reached in enabling conditions, and some limitations of such discrete models should be kept in mind.  相似文献   

An assessment of a multi-model ensemble of decadal climate predictions     

A. Bellucci  R. Haarsma  S. Gualdi  P. J. Athanasiadis  M. Caian  C. Cassou  E. Fernandez  A. Germe  J. Jungclaus  J. Kröger  D. Matei  W. Müller  H. Pohlmann  D. Salas y Melia  E. Sanchez  D. Smith  L. Terray  K. Wyser  S. Yang 《Climate Dynamics》2015,44(9-10):2787-2806

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Chronology and stratigraphy of the Magdalen Islands archipelago from the last glaciation to the early Holocene: new insights into the glacial and sea‐level history of eastern Canada          下载免费PDF全文

Audrey M. Rémillard  Guillaume St‐Onge  Pascal Bernatchez  Bernard Hétu  Jan‐Pieter Buylaert  Andrew S. Murray  Benoit Vigneault 《Boreas: An International Journal of Quaternary Research》2016,45(4):604-628

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Measuring the Reliability of Wheelchair User Route Planning based on Volunteered Geographic Information   总被引：1，自引：0，他引：1       下载免费PDF全文

Pascal Neis 《Transactions in GIS》2015,19(2):188-201

The development of a wheelchair user friendly route planning application inherits a number of special requirements and details that need to be considered during the generation of the routing graph and the corresponding algorithm, making this task much more complex than car or pedestrian related applications. Each wheelchair type and, more importantly, each individual user might have different needs with regards to the way condition or other criteria. This study proposes a new approach to route planning for wheelchair users tailored for individual and personal requirements provided by the user and the calculation of a reliability factor of the computed wheelchair path. The routing graph is based on the freely available Volunteered Geographic Information (VGI) retrieved from the OpenStreetMap (OSM) project. The newly created algorithm is evaluated and tested for a selected area in Bonn, Germany. A new reliability factor is introduced that gives direct feedback about the quality of the generated path. Similar factor estimations can also be utilized for multiple route planning applications where VGI or other commercial or administrative data is implemented and more detailed factors than a simple geometric representation of a street network are of importance.  相似文献   

Assessing the Completeness of Bicycle Trail and Lane Features in OpenStreetMap for the United States   总被引：1，自引：0，他引：1       下载免费PDF全文

Hartwig H. Hochmair  Dennis Zielstra  Pascal Neis 《Transactions in GIS》2015,19(1):63-81

This article assesses the completeness of bicycle trail and on‐street lane features in OpenStreetMap (OSM). Comparing OSM cycling features with reference data from local planning agencies for selected US Urbanized Areas shows that OSM bicycle trails tend to be more completely mapped than bicycle lanes. Manual evaluation of mapped cycling features in OSM and Google Maps for selected test areas within the Central Business Districts of Portland (OR) and Miami (FL) through comparison with governmental datasets, satellite imagery, and Google Street View, shows that the Bicycle layer in Google Maps can help to identify some missing or erroneously mapped OSM cycling links. However, Google Maps was also found to have some gaps in its data layers, suggesting that consultation of current trail and lane data from local planning authorities, if available, should be considered as an additional data source for bicycle related planning projects.  相似文献   

Diet of Haplognathia ruberrima (Gnathostomulida) in a Caribbean marine mangrove          下载免费PDF全文

Pierre‐Yves Pascal  Claude Bellemare  Wolfgang Sterrer  Henricus T. S. Boschker  Silvina Gonzalez‐Rizzo  Olivier Gros 《Marine Ecology》2015,36(2):246-257

Haplognathia ruberrima is a cosmopolitan gnathostomulid species found in sulfur bacterial mats in mangroves in Guadeloupe (French West Indies). Haplognathia ruberrima presents a δ¹³C value lower than all measured meiofaunal grazers and lower than the available measured food sources of this environment. This low δ¹³C value can not be due to specific ingestion of ¹³C‐depleted methanogenic bacteria because abundances of those bacteria are reduced in surficial and deep sediments as revealed by δ¹³C of bacterial fatty acid. According to scanning electron microscope observations, no bacterial ectosymbionts were observed at the surface of the gnathostomulids, and transmission electron microscope views revealed the absence of bacterial endosymbionts. Energy‐dispersive X‐ray spectroscopy analysis detected low levels of sulfur (0.32%±0.8) in biological tissues of H. ruberrima, confirming the absence of thioautotrophic bacterial symbionts in these animals. Consequently, the low δ¹³C value of H. ruberrima can not be due to the presence of sulfur‐oxidizing symbionts but more probably to the selective and exclusive consumption of free‐living, sulfur‐oxidizing bacteria.  相似文献   

Southern Hemisphere extra-tropical forcing: a new paradigm for El Ni?o-Southern Oscillation     

Pascal Terray 《Climate Dynamics》2011,36(11-12):2171-2199

The main goal of this paper is to shed additional light on the reciprocal dynamical linkages between mid-latitude Southern Hemisphere climate and the El Ni?o-Southern Oscillation (ENSO) signal. While our analysis confirms that ENSO is a dominant source of interannual variability in the Southern Hemisphere, it is also suggested here that subtropical dipole variability in both the Southern Indian and Atlantic Oceans triggered by Southern Hemisphere mid-latitude variability may also provide a controlling influence on ENSO in the equatorial Pacific. This subtropical forcing operates through various coupled air?Csea feedbacks involving the propagation of subtropical sea surface temperature (SST) anomalies into the deep tropics of the Atlantic and Indian Oceans from boreal winter to boreal spring and a subsequent dynamical atmospheric response to these SST anomalies linking the three tropical basins at the beginning of the boreal spring. This atmospheric response is characterized by a significant weakening of the equatorial Atlantic and Indian Inter-Tropical Convergence Zone (ITCZ). This weakened ITCZ forces an equatorial ??cold Kelvin wave?? response in the middle to upper troposphere that extends eastward from the heat sink regions into the western Pacific. By modulating the vertical temperature gradient and the stability of the atmosphere over the equatorial western Pacific Ocean, this Kelvin wave response promotes persistent zonal wind and convective anomalies over the western equatorial Pacific, which may trigger El Ni?o onset at the end of the boreal winter. These different processes explain why South Atlantic and Indian subtropical dipole time series indices are highly significant precursors of the Ni?o34 SST index several months in advance before the El Ni?o onset in the equatorial Pacific. This study illustrates that the atmospheric internal variability in the mid-latitudes of the Southern Hemisphere may significantly influence ENSO variability. However, this surprising relationship is observed only during recent decades, after the so-called 1976/1977 climate regime shift, suggesting a possible linkage with global warming or decadal fluctuations of the climate system.  相似文献