Download or read book Magnetic Helicity in the Solar Corona written by Mitchell Anthony Berger and published by . This book was released on 1984 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Helicity Spheromaks Solar Corona Loops And Astrophysical Jets written by Paul M Bellan and published by World Scientific. This book was released on 2018-03-12 with total page 653 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pedagogical in style, this book provides insights into plasma behavior valid over twenty orders of magnitude in both time and space. The book assumes that the reader has a basic knowledge of magnetohydrodynamics and explains topics using detailed theoretical analysis supported by discussion of relevant experiments. This comprehensive approach gives the reader an understanding of the essential theoretical ideas and their application to real situations.The book starts by explaining the topological concept of magnetic helicity and then develops a helicity-based model that predicts the ultimate state towards which magnetically-dominated plasmas evolve. The model predicts that no matter how messy or complicated the dynamics, a great range of plasma configurations always self-organize to a unique, simple final state. This self-organization, called relaxation, is a fundamental concept that unifies understanding of spheromaks, solar corona loops, interplanetary magnetic clouds, and astrophysical jets.After establishing why relaxation occurs, the book then examines how relaxation occurs. It shows that relaxation involves a sequence of complex non-equilibrium dynamics including fast self-collimated plasma jets, kink instabilities, magnetic reconnection, and phenomena outside the realm of magnetohydrodynamics.
Download or read book Coronal Magnetometry written by Steven Tomczyk and published by Springer. This book was released on 2016-09-10 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Captures advances being made in the field of coronal magnetism, from theory to observations and instrumentation. This volume is a collection of research articles on the subject of the solar corona, and particularly, coronal magnetism. The book was motivated by the Workshop on Coronal Magnetism: Connecting Models to Data and the Corona to the Earth, which was held 21 - 23 May 2012 in Boulder, Colorado, USA. This workshop was attended by approximately 60 researchers. Articles from this meeting are contained in this topical issue, but the topical issue also contains contributions from researchers not present at the workshop. This volume is aimed at researchers and graduate students active in solar physics. Originally published in Solar Physics, Vol. 288, Issue 2, 2013 and Vol. 289, Issue 8, 2014.
Download or read book Magnetic Helicity at the Sun in Solar Wind and Magnetospheres written by Jörg Büchner and published by . This book was released on 2003 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Helicity and Force free Equilibria in the Solar Corona and in Laboratory Devices written by Andrew Michael Dixon and published by . This book was released on 1988 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Helicity in Space and Laboratory Plasmas written by Michael R. Brown and published by American Geophysical Union. This book was released on 1999-01-26 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 111. Using the concept of magnetic helicity, physicists and mathematicians describe the topology of magnetic fields: twisting, writhing, and linkage. Mathematically, helicity is related to linking integrals, which Gauss introduced in the 19th century to describe the paths of asteroids in the sky. In the late 1970s the concept proved to be critical to understand laboratory plasma experiments on magnetic reconnection, dynamos, and magnetic field relaxation. In the late 1980s it proved equally important in understanding turbulence in the solar wind and the interplanetary magnetic field. During the last five years interest in magnetic helicity has grown dramatically in solar physics, and it will continue to grow as observations of vector magnetic fields become increasingly sophisticated.
Download or read book Helicity of the Solar Magnetic Field written by Sanjiv Kumar Tiwari and published by LAP Lambert Academic Publishing. This book was released on 2010-08 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic helicity is a physical quantity that measures the complexity in the field lines. It is given by a volume integral over scalar product of magnetic field and its vector potential. Direct computation of magnetic helicity in the solar atmosphere is not possible in want of observations to compute the volume integral. We have clarified the physical meaning of and its relation with the magnetic helicity. An analytical bipole was generated to study the effect of polarimetric noise on the estimation of various magnetic parameters. We then examined the fine structures of sunspots in terms of local current and . The concept of signed shear angle (SSA) has been introduced. Spatially averaged SSA (SASSA) gives actual twist present in a sunspot at an observed height irrespective of force-free nature and shape of sunspots. We find that there is no net current in the sunspots even in the presence of significant twist which is consistent with fibril-bundle structure of sunspot magnetic fields. The SASSA holds promise to be very useful in predicting the severity of solar flares. A good correlation has been found among the signs of helicity at different heights in the solar atmosphere.
Download or read book Magnetic Helicity Spheromaks Solar Corona Loops and Astrophysical Jets written by Paul Murray Bellan and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Origin and Dynamics of Solar Magnetism written by M.J. Thompson and published by Springer. This book was released on 2011-12-01 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Starting in 1995 numerical modeling of the Earth’s dynamo has ourished with remarkable success. Direct numerical simulation of convection-driven MHD- ow in a rotating spherical shell show magnetic elds that resemble the geomagnetic eld in many respects: they are dominated by the axial dipole of approximately the right strength, they show spatial power spectra similar to that of Earth, and the magnetic eld morphology and the temporal var- tion of the eld resembles that of the geomagnetic eld (Christensen and Wicht 2007). Some models show stochastic dipole reversals whose details agree with what has been inferred from paleomagnetic data (Glatzmaier and Roberts 1995; Kutzner and Christensen 2002; Wicht 2005). While these models represent direct numerical simulations of the fundamental MHD equations without parameterized induction effects, they do not match actual pla- tary conditions in a number of respects. Speci cally, they rotate too slowly, are much less turbulent, and use a viscosity and thermal diffusivity that is far too large in comparison to magnetic diffusivity. Because of these discrepancies, the success of geodynamo models may seem surprising. In order to better understand the extent to which the models are applicable to planetary dynamos, scaling laws that relate basic properties of the dynamo to the fundamental control parameters play an important role. In recent years rst attempts have been made to derive such scaling laws from a set of numerical simulations that span the accessible parameter space (Christensen and Tilgner 2004; Christensen and Aubert 2006).
Download or read book Determination of Magnetic Helicity in the Solar Wind and Implications for Cosmic Ray Propagation written by and published by . This book was released on 1981 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Helicities in Geophysics Astrophysics and Beyond written by Kirill Kuzanyan and published by John Wiley & Sons. This book was released on 2023-12-12 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helicities in Geophysics, Astrophysics, and Beyond Helicities play essential roles in numerous geophysical, astrophysical, and magnetohydrodynamic phenomena, thus are studied from various disciplinary viewpoints. Helicities in Geophysics, Astrophysics, and Beyond draws together experts from different research fields to present an interdisciplinary and integrated approach to helicity studies. This synthesis advances understanding of the fundamental physical processes underlying various helicity-related phenomena. Volume highlights include: Concise introduction to fundamental properties of helicities Recent developments and achievements in helicity studies Perspectives from different fields including geophysics, space physics, solar physics, plasma physics, atmospheric and nonlinear sciences A cohesive mathematical, physical, observational, experimental, and numerical strategy for helicity studies A synthesized framework for the application of helicity to real-world problems The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
Download or read book The Solar Corona written by Leon Golub and published by Cambridge University Press. This book was released on 1997-08-21 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations from the ground and space have advanced our knowledge of the solar corona dramatically over the past three decades. This timely volume presents a lucid and synthesized review of the latest observations of the solar corona and discusses how these observations have advanced and shaped our understanding of coronal physics. In the process, the authors introduce a wide variety of exciting physics, including dynamo theory and radiative transfer. They also demonstrate how the transient effects of the solar cycle effect "space weather." This book provides a much-needed introduction to coronal physics for advanced students and researchers.
Download or read book Magnetic Helicity Generation by Solar Differential Rotation written by and published by . This book was released on 2000 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Observations of sunspots, active regions, filaments, coronal arcades, and interplanetary magnetic clouds indicate that the Sun preferentially exhibits left-handed, negative-helicity features in its northern hemisphere, and their opposite counterparts in the south, independent of sunspot cycle. We investigate quantitatively the generation of magnetic helicity by solar differential rotation acting on emerged bipolar sources of flux, using analytical and numerical methods. We find that the vast majority of bipoles absorb negative helicity in the northern hemisphere and positive helicity in the south, in accord with observations. After two to four solar rotation periods have elapsed, the helicity generated by differential rotation amounts to about 10% of the bipole's squared flux. Thus, each of the approximately 1 x 10(3) large bipolar regions emergent on the Sun during sunspot cycle 21 entrained about 1 x 10(43) Mx(2) of helicity in its 1 x 10(22) Mx of flux. We show further that the roughly 5 x 10(3) coronal mass ejections and associated interplanetary magnetic clouds that departed the Sun during the cycle carried off about 5 x 10(24) Mx of flux and 1 x 10(46) Mx(2) of helicity, within a factor of two of the estimates for solar production of these quantities. Evidently, differently rotation acting on emerged bipolar sources of flux can account quantitatively for the magnetic helicity balance of the Sun and the heliosphere, as well as for the observed prevalence of negative-helicity magnetic features in the north and positive-helicity features in the south.
Download or read book Magnetohydrodynamic Modeling of the Solar Corona and Heliosphere written by Xueshang Feng and published by Springer. This book was released on 2019-08-01 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book covers intimately all the topics necessary for the development of a robust magnetohydrodynamic (MHD) code within the framework of the cell-centered finite volume method (FVM) and its applications in space weather study. First, it presents a brief review of existing MHD models in studying solar corona and the heliosphere. Then it introduces the cell-centered FVM in three-dimensional computational domain. Finally, the book presents some applications of FVM to the MHD codes on spherical coordinates in various research fields of space weather, focusing on the development of the 3D Solar-InterPlanetary space-time Conservation Element and Solution Element (SIP-CESE) MHD model and its applications to space weather studies in various aspects. The book is written for senior undergraduates, graduate students, lecturers, engineers and researchers in solar-terrestrial physics, space weather theory, modeling, and prediction, computational fluid dynamics, and MHD simulations. It helps readers to fully understand and implement a robust and versatile MHD code based on the cell-centered FVM.
Download or read book A Guide to the Solar Corona written by Donald E. Billings and published by Academic Press. This book was released on 2013-10-22 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Guide to the Solar Corona is specifically directed to the space scientist or engineer who is not a specialist in solar physics, but whose work requires a fairly detailed knowledge of the corona. It is hoped that the material may prove useful to most graduate students in astrophysics, while solar physicists may find some topics of interest and value to them. The book contains 12 chapters and begins with three descriptive chapters that provide the casual reader with a concept of the corona as it is evident through more or less direct observation. Topics covered include the development of coronal science, observational techniques, and observational aspects of the corona. The next chapter discusses methods of analyzing coronal data. Subsequent chapters present theoretical considerations as they are applicable to the corona. These combine theory with observation to provide a description of the various aspects of the corona. The final chapter is a combination of established ideas and speculation on the place of the corona in the universe.
Download or read book Theory and Observations of the Magnetic Field in the Solar Corona written by Laura Carcedo and published by . This book was released on 2005 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Helicity Changes of Solar Active Regions by Photospheric Horizontal Motions written by Y. J. Moon and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
