CNRS Environmental Sciences

Ajaccio, France

CNRS Environmental Sciences

Ajaccio, France
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The reconstruction of past climate variability offers important information about our climate system. Ice cores extracted from polar ice sheets or from mountainous glaciers are among the most popular climate archives. Ice cores from Andean glaciers in South America have been studied since the 1980's. Almost ten ice cores have been extracted from the equator to Patagonia. They cover different time periods from the last century to the last glacial-interglacial termination that started 21,000 years ago. Those ice cores are usually dated by using a combination of methods: annual layers counting in both isotopic and chemical ice composition, radionuclides concentration analysis to detect atmospheric nuclear tests during the 20th century and ice flow modeling for the deepest part of those cores. This paper presents two interesting results arising from the isotopic composition of the ice. The first one deals with the isotopic records of Bolivian (Illimani) and Peruvian (Quelccaya) ice cores in regards to the reconstruction of glacier extent during the little ice age in the 17th-18th century. Both approaches suggest a slightly moister and cooler period from 1650 to 1780. The second result arises from the 120-year long isotopic record of an ice core drilled in Patagonia (San Valentin). It suggests that at the regional scale, temperature has regularly decreased of about 0.2 °C per decade, extending the temperature decrease shown by Chilean meteorological data since the 1970's despite a global warming.


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-CA | Phase: ERANET.2008.1;SST.2008.6.0.8. | Award Amount: 1.57M | Year: 2009

ERA-NET ROAD IIs aim is to strengthen the European Research Area in road research by coordinating national and regional road research programmes and policies. The consortium comprises owners and managers of road research programmes in fifteen countries and two regions, i.e. the eleven National Road Administrations active in the first ERA-NET ROAD plus four more National Road Administrations and two Regional Road Administrations. Jointly, they will promote, develop and facilitate collaborative trans-national programming, financing and procurement of road research. ERA-NET ROAD II intends to build on the success of the first ERA-NET ROAD, which was funded under the Sixth Framework Programme. It made considerable progress towards the networking of road research programmes across Europe and was able to develop working procedures, identify common strategic research opportunities and launch a number of joint trans-national research projects. ERA-NET ROAD II will build on that work, focusing on implementation of joint activities and funding of joint trans-national research. The partners in ERA-NET ROAD II will ensure that coordination between road research programmes owners from both within and outside the Consortium is broadened and deepened, and new partners will be invited to join the consortium. Two trans-nationally funded programme calls will pave the way towards achieving an expenditure of 10% of public road research budgets on collaborative research by 2013. The project will also liaise with other public and private stakeholders in transport research programming in Europe and encourage collaboration with non-European research programmes. At the end of the project, collaborative research will have become business as usual for National Road Administrations. A permanent and self-sustaining structure will have been established and embedded that will take forward the trans-national coordination of road research programmes after completion of the project.


Grant
Agency: European Commission | Branch: FP7 | Program: CSA-CA | Phase: SST-2007-6.0-07 | Award Amount: 3.16M | Year: 2008

ERA-NET TRANSPORT II (ENT II) brings together the owners of national transport re-search programmes from thirteen countries, representing an annual public funding volume in the access of 300 Mio in total. The vision behind ENT is to supplement and enrich na-tional RTD programmes through trans-national cooperation where national programme representatives can see an added value. Since 2003 the ENT has facilitated several successful and valuable cooperations between national RTD programmes. ERA-NET TRANSPORT II will further develop the cooperative ENT framework for trans-national transport research programming, thereby supporting the owners of national programmes in trans-national cooperation. ENT II will further step up the level of cooperation with the minimum goals of three joint calls, one ERA-Net plus and one joint programme. ERA-NET TRANSPORT is based on three fundamental principles: voluntarity of participation and variable geometry of cooperation actions, sovereignty of national programmes and openness to new partners. The ERA-NET TRANSPORT II will further increase the cohesion and knowledge base of the network, develop more intensive and comprehensive cooperation actions between national programmes with focus on joint calls and joint programming, develop further cooperation between national programmes and the EC, such as it is envisaged for the schemes of ENT plus and Article 169 initiatives, streamline support measures and mechanisms to ensure smoother processes both nationally and through the coordination of research funding activities initiated in ENT, actively contribute to the development of a coherent Transport ERA by networking with European and international stakeholders and broaden its geographical scope by including more countries in the ERA-NET TRANSPORT.


Diaf S.,Renewable Energy Development Center Algeria | Notton G.,CNRS Environmental Sciences
Renewable and Sustainable Energy Reviews | Year: 2013

This paper presents the wind energy potential and economic analysis in five selected locations in the southern region of Algeria using wind speed data collected over a period of twelve years. The technical and economic evaluations of electricity generation from four commercial wind turbine models used for electricity generation located in these sites are examined. The wind speed data analysis shows that the sites located in the southern region of Algeria, except Tamanrasset, have a good wind potential for the wind energy development. The highest potential wind power was found at Adrar, with 88% of the time the wind speed is above 3 m/s. The yearly energy output, the capacity factor and the wind energy cost per unit of electricity generated by the selected wind turbines are calculated. In terms of energy production, the results show that Adrar is the best location for harnessing the wind power to generate electricity. The maximum energy output of 9429.8 MW h is found for Fuhrlander FL 2500 wind machine at Adrar. The capacity factor values are found to vary from a minimum of 13% at Tamanrasset and a maximum of 48% in Adrar. In addition, the results show that the minimum cost per kW h of electricity generated is found to be 0.01204 $/kW h for Suzlon S82/1.5MW wind turbine in Adrar, while the maximum value reaches 0.0923 $/kW h for the Fuhrlander FL 2500/901 in Tamanrasset. Among all the considered models, the Suzlon S82/1.5MW wind turbine is found to be the most attractive in terms of the cost per kW h. According to the obtained results, the wind resource appears to be suitable for power production in the southern region, which makes it a viable substitute to diesel oil for electricity generation. © 2013 Elsevier Ltd.


Diaf S.,Renewable Energy Development Center Algeria | Notton G.,CNRS Environmental Sciences
Renewable and Sustainable Energy Reviews | Year: 2013

In this study, the wind energy potential and economic analysis in 13 locations are investigated using wind speed data measured at 10 m height. From the collected data which are the daily, monthly and frequency profiles of the wind speed at these sites, the southern region of Algeria is found to have the relatively highest wind potential. Technical and economic evaluations of electricity generation from different commercial wind turbines are examined. The yearly energy output, capacity factor and electrical energy cost of kWh produced by the selected wind turbines are calculated. In term of energy production, the results show that Adrar is the best location for harnessing the wind power and generating electricity. The capacity factors are found to vary from 6% at Skikda to 48% at Adrar. In addition, it was found that the minimum cost per kWh of electricity generated is about 0.0179 $/kWh at Adrar for the southern region, 0.0431 $/kWh at Oran for the coastal region and 0.0518 $/kWh at Setif for the highland region. Among all the considered models, the Suzlon S82-1500 wind turbine is found to be the most attractive in terms of cost per kWh. Based on the obtained results, the wind resource appears to be suitable for power production in the southern region, which makes it a viable substitute to diesel oil for electricity generation. © 2012 Elsevier Ltd.


Filippi J.-B.,CNRS Environmental Sciences | Pialat X.,CNRS Environmental Sciences | Clements C.B.,San Jose State University
Proceedings of the Combustion Institute | Year: 2013

Numerical simulations using a coupled approach between Meso-NH (Non-Hydrostatic) LES (Large Eddy Simulation) mesoscale atmospheric model and ForeFire wildland fire area simulator are compared to experimental data to assess the performance of the proposed coupled approach in predicting fine-scale properties of the dynamics of wildland fires. Meso-NH is a non-hydrostatic, large eddy simulation capable, atmospheric research model. ForeFire insures a front tracking of the fire front by means of Lagrangian markers evolving on the earth's surface according to a physical rate-of-spread model. The atmospheric model forces the fire behavior through the surface wind field, whereas the fire forces the atmosphere simulation through surface boundary conditions of heat and vapor fluxes. The FireFlux experiment, an experimental 32 Ha burn of tall grass instrumented with wind profilers and thermocouples, was designed specifically to estimate the atmospheric perturbation introduced by wildland fire. Comparisons of the simulations at different resolutions with the large-scale experiment validate the chosen coupling methodology and the choice of a coupled approach with a meso-scale atmospheric model for the prediction of wildland fire propagation. Distinct fire propagation behavior is simulated between coupled and non-coupled simulation. While the simulations did not reproduce high frequency perturbations, it is shown that the atmospheric model captures well atmospheric perturbations induced by combustion at the ground level in terms of behavior and amplitude. © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.


Motte F.,CNRS Environmental Sciences | Notton G.,CNRS Environmental Sciences | Cristofari C.,CNRS Environmental Sciences | Canaletti J.-L.,CNRS Environmental Sciences
Applied Energy | Year: 2013

A new concept of flat plate solar collector is presented: its originality comes from its remarkable shape and from its integration into a rainwater gutter. The complete solar collector consists in several short modules connected serially. After a brief presentation of the building energy problem, the new patented solar collector is described and the two thermal experimentations are shown. A numerical model is developed in Matlab® environment using a finite difference model and an electrical analogy. At last, the thermal model is validated from experimental data under various meteorological situations. The adequacy of the model with the experimental data is shown for various temperatures inside the solar collector and for the water temperatures. © 2012 Elsevier Ltd.


Baile R.,CNRS Environmental Sciences | Muzy J.-F.,CNRS Environmental Sciences
Physical Review Letters | Year: 2010

We study various hourly surface layer wind series recorded at different sites in the Netherlands by the "Royal Netherlands Meteorological Institute." By reporting all velocity magnitude correlation coefficients, associated with the available couples of locations, as a function of their spatial distance, we find that they fall on a single curve. This curve turns out to be remarkably well described by a logarithmic shape, characteristic of continuous cascades with an intermittency coefficient λ20.04 and an integral scale L 600km. Along the same line, we study the scaling properties of spatial velocity increment structure functions. This allows one to estimate the ζ(q) spectrum and to confirm an intermittent nature of mesoscale fluctuations similar to the one observed in fully developed turbulence. © 2010 The American Physical Society.


Notton G.,CNRS Environmental Sciences
Renewable and Sustainable Energy Reviews | Year: 2015

The islands are often not or only partially connected to continental electrical networks and have to manage their energy supplies in reaching themselves the production/demand balance while ensuring the quality of the delivered electricity. The low consumption and the lack of interconnections induce higher energy costs than in other regions. For increasing their security, the islands prefer to use indigenous sources as renewable ones; unfortunately, the intermittence and stochastic character of these "fatal" energy sources make them more difficult to manage and it is aggravated in the case of small island networks. The islands are good locations for using and testing new technologies of energy production and storage. Most islands have a good renewable energy (RE) potential often underused. The difficulties of electricity management in island grids are first shown particularly with the impact on the energy production cost. Then, the problem of the integration of renewable energy sources (RES) in island electrical grids is highlighted. The energy situation of French islands is presented with a particular focus on the part of renewable sources. A higher share of renewable energy in the energy mix can be reached only with the development of the energy production efficient prediction, with the development of energy storage means and with an optimal management of the energy flux via the utilization of smart grids. © 2015 Elsevier Ltd. All rights reserved.


A method for reducing the rollover risk of an automotive vehicle includes:

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