From Coronal Observations to MHD Simulations, the Building Blocks for 3D Models of Solar Flares (Invited Review)

2016 ◽  
pp. 47-78
Author(s):  
M. Janvier ◽  
G. Aulanier ◽  
P. Démoulin
Keyword(s):  
Solar Flares ◽  
Building Blocks ◽  
3D Models ◽  
Mhd Simulations

scholarly journals Similarities between extreme events in the solar-terrestrial system by means of nonextensivity

2011 ◽  
Vol 18 (5) ◽  
pp. 563-572 ◽  
Author(s):  
G. Balasis ◽  
C. Papadimitriou ◽  
I. A. Daglis ◽  
A. Anastasiadis ◽  
I. Sandberg ◽  
...  
Keyword(s):  
Extreme Events ◽  
Solar Flares ◽  
Particle Physics ◽  
Building Blocks ◽  
Magnetic Storms ◽  
Earthquake Dynamics ◽  
Magnitude Distribution ◽  
Terrestrial System ◽  
Universal Principles ◽  
Elementary Building

Abstract. The dynamics of complex systems are founded on universal principles that can be used to describe disparate problems ranging from particle physics to economies of societies. A corollary is that transferring ideas and results from investigators in hitherto disparate areas will cross-fertilize and lead to important new results. In this contribution, we investigate the existence of a universal behavior, if any, in solar flares, magnetic storms, earthquakes and pre-seismic electromagnetic (EM) emissions, extending the work recently published by Balasis et al. (2011a). A common characteristic in the dynamics of the above-mentioned phenomena is that their energy release is basically fragmentary, i.e. the associated events are being composed of elementary building blocks. By analogy with earthquakes, the magnitude of the magnetic storms, solar flares and pre-seismic EM emissions can be appropriately defined. Then the key question we can ask in the frame of complexity is whether the magnitude distribution of earthquakes, magnetic storms, solar flares and pre-fracture EM emissions obeys the same law. We show that these apparently different extreme events, which occur in the solar-terrestrial system, follow the same energy distribution function. The latter was originally derived for earthquake dynamics in the framework of nonextensive Tsallis statistics.

scholarly journals A New 3D Model Retrieval Method with Building Blocks

2009 ◽  
Vol 2009 ◽  
pp. 1-6 ◽  
Author(s):  
Mingquan Zhou ◽  
Qingsong Huo ◽  
Guohua Geng ◽  
Xiaojing Liu
Keyword(s):  
3D Model ◽  
Building Blocks ◽  
3D Models ◽  
3D Model Retrieval ◽  
Virtual Space ◽  
3D Data ◽  
Model Retrieval ◽  
Voxel Model ◽  
Interactive 3D ◽  
Application Fields

As the numbers of 3D models available grow in many application fields, there is an increasing need for a search method to help people find them. Unfortunately, traditional search techniques are not always effective for 3D data. In this paper, we describe a novel method of interactive 3D model retrieval with building blocks. First, by using a cube block as the baseblock in a 3D virtual space, we may construct the query model with human-computer interaction method. Then through retrieving the polygon model of the database generated by the voxel model, we may get retrieval results in real time. Experiments are conducted to evaluate the performance of the proposed method.

scholarly journals Flare particle acceleration in the interaction of twisted coronal flux ropes

2018 ◽  
Vol 611 ◽  
pp. A40 ◽  
Author(s):  
J. Threlfall ◽  
A. W. Hood ◽  
P. K. Browning
Keyword(s):  
Particle Acceleration ◽  
Solar Flares ◽  
Three Dimensional ◽  
Coronal Loops ◽  
Mhd Simulation ◽  
Mhd Simulations ◽  
Uniform Background ◽  
Energy Gains ◽  
Particle Behaviour

Aim. The aim of this work is to investigate and characterise non-thermal particle behaviour in a three-dimensional (3D) magnetohydrodynamical (MHD) model of unstable multi-threaded flaring coronal loops.Methods. We have used a numerical scheme which solves the relativistic guiding centre approximation to study the motion of electrons and protons. The scheme uses snapshots from high resolution numerical MHD simulations of coronal loops containing two threads, where a single thread becomes unstable and (in one case) destabilises and merges with an additional thread.Results. The particle responses to the reconnection and fragmentation in MHD simulations of two loop threads are examined in detail. We illustrate the role played by uniform background resistivity and distinguish this from the role of anomalous resistivity using orbits in an MHD simulation where only one thread becomes unstable without destabilising further loop threads. We examine the (scalable) orbit energy gains and final positions recovered at different stages of a second MHD simulation wherein a secondary loop thread is destabilised by (and merges with) the first thread. We compare these results with other theoretical particle acceleration models in the context of observed energetic particle populations during solar flares.

scholarly journals Geological Contributions to Geometallurgy: A Review

2017 ◽  
Vol 44 (3) ◽  
pp. 103-118 ◽  
Author(s):  
Julie A. Hunt ◽  
Ron F. Berry
Keyword(s):  
Value Chain ◽  
Cost Benefit ◽  
Building Blocks ◽  
3D Models ◽  
Spatial Modelling ◽  
Test Methods ◽  
Mine Planning ◽  
Rock Properties ◽  
Sample Distribution ◽  
The Cost

Geometallurgy is a cross-disciplinary science that addresses the problem of teasing out the features of the rock mass that significantly influence mining and processing. Rocks are complex composite mixtures for which the basic building blocks are grains of minerals. The properties of the minerals, how they are bound together, and many other aspects of rock texture affect the entire mining value chain from exploration, through mining and processing, waste and tailings disposal, to refining and sales. This review presents rock properties (e.g. strength, composition, mineralogy, texture) significant in geometallurgy and examples of test methods available to measure or predict these properties.   Geometallurgical data need to be quantitative and spatially constrained so they can be used in 3D modelling and mine planning. They also need to be obtainable relatively cheaply in order to be abundant enough to provide a statistically valid sample distribution for spatial modelling. Strong communication between different departments along the mining value chain is imperative so that data are produced and transferred in a useable form and duplication is avoided. The ultimate aim is to have 3D models that not only show the grade of valuable elements (or minerals), but also include rock properties that may influence mining and processing, so that decisions concerning mining and processing can be made holistically, i.e. the impacts of rock properties on all the cost centres in the mining process are taken into account. There are significant costs to improving ore deposit knowledge and it is very important to consider the cost-benefit curve when planning the level of geometallurgical effort that is appropriate in individual deposits.RÉSUMÉLa géométallurgie est une science interdisciplinaire qui s’intéresse aux caractéristiques de la masse rocheuse qui influent de manière significative sur l'exploitation minière et le traitement du minerai. Les roches sont des mélanges composites complexes dont les éléments structurant de base sont des grains de minéraux. Les propriétés des minéraux, la façon dont ils sont liés entre eux, et de nombreux autres aspects de la texture des roches déterminent l'ensemble de la chaîne de valeur minière, de l'exploration à l'extraction à la transformation, à l'élimination des déchets et des résidus, jusqu'au raffinage et à la vente. La présente étude passe en revue les propriétés significatives de la roche (par ex. sa cohésion, sa composition, sa minéralogie, sa texture) en géométallurgie ainsi que des exemples de méthodes d'essai disponibles pour mesurer ou prédire ces propriétés.   Les données géométallurgiques doivent être quantitatives et localisées spatialement afin qu'elles puissent être utilisées dans la modélisation 3D et la planification de la mine. Elles doivent également être peu couteuses afin d'être suffisamment nombreuses pour fournir une distribution d'échantillon statistiquement valide pour la modélisation spatiale. Une communication efficace entre les différents segments de la chaîne de valeur minière est impérative pour que les données soient produites et transférées sous une forme utilisable et que les duplications soient évitées. Le but ultime est d'avoir des modèles 3D qui montrent non seulement la qualité des éléments précieux (ou minéraux), mais aussi les propriétés de roche qui déterminent l'exploitation minière et le traitement du minerai, de sorte que les décisions concernant l'exploitation minière et le traitement du minerai peuvent être réalisées de façon holistique, c.-à-d. que l’impact des propriétés de roche sur tous les maillons de la chaîne des coûts du processus minier sont prises en compte. Les coûts d’amélioration des connaissances sur le gisement de minerai étant importants, il faut tenir compte de la courbe coûts-bénéfices lors de la planification du niveau d'investissement géométallurgique approprié pour le gisement considéré.

scholarly journals Three-Dimensional Simulation Study of Plasmoid Injection into Magnetized Plasma

1998 ◽  
Vol 188 ◽  
pp. 209-210
Author(s):  
Y. Suzuki ◽  
T.-H. Watanabe ◽  
A. Kageyama ◽  
T. Sato ◽  
T. Hayashi
Keyword(s):  
Solar Wind ◽  
Simulation Study ◽  
Solar Flares ◽  
Interplanetary Medium ◽  
Three Dimensional ◽  
Magnetized Plasma ◽  
Important Process ◽  
Plasma Region ◽  
Mhd Simulations ◽  
Dimensional Simulation

Resent observations suggest that, during solar flares, plasmoids are injected into the interplanetary medium (Stewart et al., 1982). It has also been pointed out that solar wind irregularities modeled as plasmoids are penetrated into the magnetosphere (Lemaire, 1977). These plasmoid injections are considered to be an important process because they transfer mass, momentum, and energy into such magnetized plasma regions. Our objective is to investigate the dynamics of a plasmoid, which is injected into a magnetized plasma region and to reveal mechanisms to transfer them. To achieve this, we carried out three-dimensional magnetohydrodynamic (MHD) simulations.

scholarly journals Resistive Processes in the Preflare Phase of Eruptive Flares

1998 ◽  
Vol 188 ◽  
pp. 207-208
Author(s):  
T. Magara ◽  
K. Shibata
Keyword(s):  
Current Sheet ◽  
Current Density ◽  
Solar Flares ◽  
Magnetic Pressure ◽  
Anomalous Resistivity ◽  
Magnetic Island ◽  
Tearing Instability ◽  
Mhd Simulations ◽  
A Current

In this study, we perform 2.5-dimensional MHD simulations and clarify the role of perpendicular magnetic fields (which are perpendicular to the 2D plane) in a preflare current sheet of solar flares. At the first stage, a current sheet formed within a coronal magnetic structure is filled with the perpendicular fields (force-free structure). Then this sheet begins to be dissipated through the tearing instability under a uniform resistivity. As the instability proceeds, the distribution of the perpendicular fields vary in such a way that most of them gather around O-point (magnetic island) instead of X-point. Therefore, the magnetic pressure of these fields weaken in the vicinity of X-point so that they no longer suppress the inflows toward this point. These flows then make the current sheet thinner and thinner, which implies that the current density around X-point becomes high enough to cause an anomalous resistivity whose value is much larger than that of the normal collisional resistivity. In this way, the transition from a uniform resistivity to a locally-enhanced one occurs, which can make the violent energy release observed in solar flares.

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