Extension of SPIS to simulate dust electrostatic charging, transport and contamination of lunar probes

A modification of the Spacecraft Plasma Interaction Software has been undertaken under ESA contract 4000107327/12/NL/AK (SPIS-DUST). The primary goal is to provide mission designers with an engineering tool capable of predicting charged dust behavior in a given plasma environment involving a spacecraft / exploration unit in contact with complex topological features at various locations of the Moon’s surface. The tool also aims at facilitating dust contamination diagnostics for sensitive surfaces such as sensors optics, solar panels, thermal interfaces, etc. In this paper, the new user interface and the new numerical solvers developed in the frame of this project is presented. The pre-processing includes the building of a 3D lunar surface from a topology description (i.e. a point list), an interface to position the spacecraft and a merging interface for the spacecraft elements in contact with the lunar surface. Concerning the physical models, the new solvers have been developed in order to model the physics of the ejection of the dust from the soils, the dusts charging and transport in volume and the dust interaction and contamination of the spacecraft. The post-processing includes the standard outputs of SPIS for the electrostatic computation and the plasma plus dedicated instruments for the diagnosis of the dusts. A set of verification test cases are presented in order to demonstrate the new capabilities of this version of SPIS in realistic conditions

New SPIS capabilities to simulate dust electrostatic charging, transport, and contamination of lunar probes

The spacecraft-plasma interaction simulator has been improved to allow for the simulation of lunar and asteroid dust emission, transport, deposition, and interaction with a spacecraft on or close to the lunar surface. The physics of dust charging and of the forces that they are subject to has been carefully implemented in the code. It is both a tool to address the risks faced by lunar probes on the surface and a tool to study the dust transport physics. We hereby present the details of the physics that has been implemented in the code as well as the interface improvements that allow for a user-friendly insertion of the lunar topology and of the lander in the simulation domain. A realistic case is presented that highlights the capabilities of the code as well as some general results about the interaction between a probe and a dusty environment

Revisiting and modelling the woodland farming system of the early Neolithic Linear Pottery Culture (LBK), 5600–4900 B.C

International audienceThis article presents the conception and the conceptual results of a modelling representation of the farming systems of the Linearbandkeramik Culture (LBK). Assuming that there were permanent fields (PF) then, we suggest four ways that support the sustainability of such a farming system over time: a generalized pollarding and coppicing of trees to increase the productivity of woodland areas for foddering more livestock, which itself can then provide more manure for the fields, a generalized use of pulses grown together with cereals during the same cropping season, thereby reducing the needs for manure. Along with assumptions limiting bias on village and family organizations, the conceptual model which we propose for human environment in the LBK aims to be sustainable for long periods and can thereby overcome doubts about the PFs hypothesis for the LBK farming system. Thanks to a reconstruction of the climate of western Europe and the consequent vegetation pattern and productivity arising from it, we propose a protocol of experiments and validation procedures for both testing the PFs hypothesis and defining its eco-geographical area

Position chronologique du renne (Rangifer tarandus L.) à la fin du Tardiglaciaire dans les Alpes du Nord françaises et le Jura méridional

Afin de documenter la présence et la disparition du renne (Rangifer tarandus L.) du Jura méridional et des Alpes du Nord françaises, une vingtaine de datations sur ossements de renne ont été réalisées dans le cadre d'un Projet Collectif de Recherche sur la fin du Tardiglaciaire dans ces régions. Les dates obtenues montrent que le renne est attesté entre 14500 et 12100 B.P. (15500-12100 av. J-C.) dans les sites de basse et moyenne altitude. Ces résultats sont discutés à l'échelle régionale, en relation avec d'autres données paléoenvironnementales. Une évaluation critique de la composition de certains spectres fauniques dont la position chronologique est mal définie, est ensuite menée dans une optique comparative. La perduration tardive du renne est enfin discutée à l'échelle de la France et des régions septentrionales voisines

Extension of SPIS to simulate dust electrostatic charging, transport and contamination of lunar probes

A modification of the Spacecraft Plasma Interaction Software has been undertaken under ESA contract 4000107327/12/NL/AK (SPIS-DUST). The primary goal is to provide mission designers with an engineering tool capable of predicting charged dust behavior in a given plasma environment involving a spacecraft / exploration unit in contact with complex topological features at various locations of the Moon’s surface. The tool also aims at facilitating dust contamination diagnostics for sensitive surfaces such as sensors optics, solar panels, thermal interfaces, etc. In this paper, the new user interface and the new numerical solvers developed in the frame of this project is presented. The pre-processing includes the building of a 3D lunar surface from a topology description (i.e. a point list), an interface to position the spacecraft and a merging interface for the spacecraft elements in contact with the lunar surface. Concerning the physical models, the new solvers have been developed in order to model the physics of the ejection of the dust from the soils, the dusts charging and transport in volume and the dust interaction and contamination of the spacecraft. The post-processing includes the standard outputs of SPIS for the electrostatic computation and the plasma plus dedicated instruments for the diagnosis of the dusts. A set of verification test cases are presented in order to demonstrate the new capabilities of this version of SPIS in realistic conditions

Position chronologique du renne (Rangifer tarandus L.) à la fin du Tardiglaciaire dans les Alpes française du nord et le Jura méridional

International audienceRadiocarbon dating of archaeological reindeer (Rangifer tarandus L.) remains has been conducted in order to chart its presence through the Late Glacial in southern Jura and northern French Alps. About twenty dates have been successfully obtained, suggesting that reindeer is continuously attested between ca 14500 and 12100 BP (ca 15500-12100 CAL BC) in the sites settled up to 1200 m. These results are then discussed in relation with other palaeoenvironmental regional data. A critical analysis of faunal spectra from different chronocultural contexts is conducted in a comparative perspective. The late occurence of reindeer in various regions of France and in northern areas is debated.Afin de documenter la présence et la disparition du renne (Rangifer tarandus L.) du Jura méridional et des Alpes du Nord françaises, une vingtaine de datations sur ossements de renne ont été réalisées dans le cadre d’un Projet Collectif de Recherche sur la fin du Tardiglaciaire dans ces régions. Les dates obtenues montrent que le renne est attesté entre 14 500 et 12 100 BP (15 500-12 100 av. J-C.) dans les sites de basse et moyenne altitude. Ces résultats sont discutés à l’échelle régionale, en relation avec d’autres données paléoenvironnementales. Une évaluation critique de la composition de certains spectres fauniques dont la position chronologique est mal définie, est ensuite menée dans une optique comparative. La perduration tardive du renne est enfin discutée à l'échelle de la France et des régions septentrionales voisines

Systèmes agrosylvopastoraux oleaster-olive greffés dans le nord du Maroc

International audienceThis book has been published by Allenvi (French National Alliance for Environmental Research) to coincide with the 22nd Conference of Parties to the United Nations Framework Convention on Climate Change (COP22) in Marrakesh. It is the outcome of work by academic researchers on both sides of the Mediterranean and provides a remarkable scientific review of the mechanisms of climate change and its impacts on the environment, the economy, health and Mediterranean societies. It will also be valuable in developing responses that draw on “scientific evidence” to address the issues of adaptation, resource conservation, solutions and risk prevention. Reflecting the full complexity of the Mediterranean environment, the book is a major scientific contribution to the climate issue, where various scientific considerations converge to break down the boundaries between disciplines.Cet ouvrage, publié par l’Alliance nationale de recherche sur l’environnement (Allenvi) à l’occasion de la 22e Conférence des Parties de la Convention Cadre des Nations unies sur le changement climatique (COP22) de Marrakech, est le fruit de la mobilisation de chercheurs et d’universitaires des deux rives de la Méditerranée. Il constitue une synthèse scientifique exceptionnelle sur les mécanismes du changement climatique, ses impacts sur l’environnement, l’économie, la santé et les sociétés de la Méditerranée. Il représente par ailleurs un précieux outil pour élaborer des réponses, fondées sur l’ « évidence scientifique », en matière d’adaptation, de conservation des ressources, de solutions ou de prévention des risques. Mettant en exergue toute la complexité de l’environnement méditerranéen, cet ouvrage est une contribution scientifique majeure à la question climatique, au croisement des questionnements scientifiques dans une perspective de décloisonnement disciplinaire

Evolution and management of the ligneous vegetation during the neolithic: chacoal analysis of two sheepfold caves in Provence (south of France) : (Pendimoun & Perthus II, France)

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