Download or read book Magnetic Field Extrapolation in the Solar Corona and Observations of a Flux Rope in the Solar Wind written by Peng Ruan and published by . This book was released on 2009 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetic Flux Ropes From the Sun to the Earth and Beyond written by Rui Liu and published by Frontiers Media SA. This book was released on 2020-12-31 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This eBook is a collection of articles from a Frontiers Research Topic. Frontiers Research Topics are very popular trademarks of the Frontiers Journals Series: they are collections of at least ten articles, all centered on a particular subject. With their unique mix of varied contributions from Original Research to Review Articles, Frontiers Research Topics unify the most influential researchers, the latest key findings and historical advances in a hot research area! Find out more on how to host your own Frontiers Research Topic or contribute to one as an author by contacting the Frontiers Editorial Office: frontiersin.org/about/contact.
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 Formation and Eruption of Coronal Magnetic Flux Ropes written by Alexander William James and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coronal Expansion and Solar Wind written by A. J. Hundhausen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Little more than ten years have passed since spaceprobe-borne instruments con clusively demonstrated the existence of the solar wind. These observations con firmed the basic validity of a theoretical model, first proposed by E. N. Parker, predicting a continuous, rapid expansion of the solar corona. The subsequent decade has seen a tremendous growth in both the breadth and sophistication of solar wind observations; the properties of the interplanetary plasma near the orbit of the earth are now known in great detail. The theory of the coronal ex pansion has also been highly refilled both in the sense of including additional physical processes, and of treating more realistic (time-dependent and non spheri cally-symmetric) coronal boundary conditions. The present volume is an attempt to synthesize the solar wind observations and coronal expansion models from this decade of rapid development. The ultimate goal is, of course, the interpretation of observed solar wind phenomena as the effects of basic physical processes occurring in the coronal and interplanetary plasma and as the natural manifestations of solar properties and structures. This approach implies an emphasis upon the "large-scale" features revealed by the observations. It requires extensive use of the concepts and methods of fluid mechanics.
Download or read book Coronal Holes and Solar Wind Acceleration written by John L. Kohl and published by Springer Science & Business Media. This book was released on 2013-11-09 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The SOHO-7 Workshop was held from 28 September through 1 October 1998 at the Asticou Inn in Northeast Harbor, Maine. The primary topic of this Workshop was the impact of SOHO observations on our understanding of the nature and evolution of coronal holes and the acceleration and composition of the solar wind. The presentations and discussions occasionally went beyond this topic to include the impact of the reported research on other solar structures and the heliosphere. SOHO (the Solar and Heliospheric Observatory), a project of international cooperation between ESA and NASA, was launched in December 1995 and began its science operations during the first few months of 1996. To many solar and space physicists, it was a great advantage that SOHO began itscomprehensive look at the Sun during the 1996 solar minimum. The qualitatively simple two-phase corona, with polar coronal holes expanding into the high-speed solar wind, and a steady equatorial streamer belt related somehow to the stochastic slow-speed solar wind, allowed various SOHO diagnostics to be initiated with a reasonably well understoodcircumsolar geometry. The analysis of subsequentSOHO measurements made during the rising phase of solar cycle 23 will continue to benefit from what has been learned from the first two years of data.
Download or read book Coronal Magnetometry written by Steven Tomczyk and published by Springer. This book was released on 2014-10-30 with total page 217 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 Data driven MHD Novel Applications to the Solar Atmosphere written by Abhishek Kumar Srivastava and published by Frontiers Media SA. This book was released on 2021-12-21 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Magnetic Solar Photosphere and Corona written by Xudong Sun and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Sun's magnetic field drives the dynamic behavior of its atmosphere and modulates the space weather conditions that we experience at the Earth. This dissertation focuses on the recent advances in understanding magnetic field measurements, static-state modeling of the corona, and their applications in space weather forecasting. We revisit the full-Sun line-of-sight magnetic field data archive from the Michelson Doppler Imager (MDI). Using the Wang-Sheeley-Arge (WSA) model coupled with the potential field source surface (PFSS) model, we retrospectively optimize the space weather forecasting scheme for the MDI data. We evaluate the long-term performance of the model: the solar wind speed prediction near the Earth yields a 16% error over solar cycle 23, and the interplanetary magnetic field polarity is correctly predicted 81% of time. The prediction accuracy is strongly correlated with the activity cycle phase. We design a new interpolation scheme to estimate the unobserved magnetic field in the polar region which improves the solar wind speed prediction. Making use of the PFSS model and the MDI data, we characterize the global-scale coronal and heliospheric magnetic field structure and its evolution during cycle 23. The modeled features agree reasonably well with remote-sensing and in-situ observations. The recent cycle displayed an extended minimum activity period, whose peculiar heliospheric consequences can be partly explained by a reduction of the polar magnetic field strength. The PFSS model may need to adopt a smaller source surface radius to better fit some observations. We use a series of vector magnetograms from the Heliospheric and Magnetic Imager (HMI) to study the magnetic field and energy evolution of NOAA active region (AR) 11158. With the aid of a non-linear force-free field (NLFFF) extrapolation, we find substantial electric current and magnetic free energy increase during early flux emergence. The computed free energy is enough to power the ensuing X-class flare. We find a step-wise energy decrease during the flare, but the value is likely underestimated. The new observations confirm the rapid and irreversible change of the photospheric field during a major flare. The horizontal field was enhanced, with the field becoming more inclined and more parallel to the polarity inversion line. Such change is consistent with the conjectured coronal field "implosion". Observation and modeling of this AR also illustrates the important role of magnetic topology. A small bipole emerged in the sunspot complex, subsequently created a quadrupolar flux system, and induced a series of eruptions with highly inclined trajectory. Field extrapolation suggests complicated magnetic connectivity with a coronal null point, which is supported by coronal observations. Owing to the asymmetrical photospheric flux distribution, the confining magnetic pressure decreases much faster horizontally than upward, and thus likely guided the non-radial eruption during its initial stage.
Download or read book Physics of the Solar Corona and Transition Region written by Oddbjorn Engvold and published by Springer Science & Business Media. This book was released on 2001-06-30 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the Monterey Workshop, held in Monterey, California, August 1999
Download or read book Plasma Properties and Magnetic Field Structure of the Solar Corona Based on Coordinated Max 1991 Observations from Serts the Vla and Magnetographs written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-09 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purposes of this investigation are to use existing, calibrated, coaligned sets of coordinated multiwaveband observations of the Sun to determine the coronal magnetic field strength and structure, and interpret the collective observations in terms of a self-consistent model of the coronal plasma and magnetic field. This information is vital to understanding processes such as coronal heating, solar wind acceleration, pre-flare energy storage, and active region evolution. Understanding these processes is the central theme of Max '91, the NASA-supported series of solar observing campaigns under which the observations acquired for this work were obtained. The observations came from NASA/GSFC's Solar EUV Rocket Telescope and Spectrograph (SERTS), the Very Large Array (VLA), and magnetographs. The technique of calculating the coronal magnetic field is to establish the contributions to the microwave emission from the two main emission mechanisms: thermal bremsstrahlung and thermal gyroemission. This is done by using the EUV emission to determine values of the coronal plasma quantities needed to calculate the thermal bremsstrahlung contribution to the microwave emission. Once the microwave emission mechanism(s) are determined, the coronal magnetic field can be calculated. A comparison of the coronal magnetic field derived from the coordinated multiwaveband observations with extrapolations from photospheric magnetograms will provide insight into the nature of the coronal magnetic field. Brosius, Jeffrey W. Unspecified Center NASW-4933...
Download or read book Exploring the Solar Wind written by Marian Lazar and published by BoD – Books on Demand. This book was released on 2012-03-21 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of a selection of original papers of the leading scientists in the fields of Space and Planetary Physics, Solar and Space Plasma Physics with important contributions to the theory, modeling and experimental techniques of the solar wind exploration. Its purpose is to provide the means for interested readers to become familiar with the current knowledge of the solar wind formation and elemental composition, the interplanetary dynamical evolution and acceleration of the charged plasma particles, and the guiding magnetic field that connects to the magnetospheric field lines and adjusts the effects of the solar wind on Earth. I am convinced that most of the research scientists actively working in these fields will find in this book many new and interesting ideas.
Download or read book Global Scale Magnetic Field Extrapolation in the Solar Corona Using a Yin Yang Grid written by Argyrios Koumtzis and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The solar magnetic field significantly influences and structures the solar coronal plasma as magnetic forces are the dominant forces within the solar corona. Therefore, an in-depth understanding of the phenomena that occur there requires the best possible description of the coronal magnetic field. Prominent instances of such phenomena include solar flares, which are abrupt discharges of electromagnetic energy observed through the whole electromagnetic spectrum. Solar flares can unleash as much energy as a billion atomic bombs in just a matter of minutes. Other crucial phenomena are coronal ...
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Dynamics of the Coronal Magnetic Field written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-11 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last few years have seen a marked increase in the sophistication of models of the solar corona. This has been brought about by a confluence of three key elements. First, the collection of high-resolution observations of the Sun, both in space and time, has grown tremendously. The SOHO (Solar Heliospheric Observatory) mission is providing additional correlated high-resolution magnetic, white-light and spectroscopic observations. Second, the power and availability of supercomputers has made two- and three-dimensional modeling routine. Third, the sophistication of the models themselves, both in their geometrical realism and in the detailed physics that has been included, has improved significantly. The support from our current Space Physics Theory grant has allowed us to exploit this confluence of capabilities. We have carried out direct comparisons between observations and models of the solar corona. The agreement between simulated coronal structure and observations has verified that the models are mature enough for detailed analysis, as we will describe. The development of this capability is especially timely, since observations obtained from three space missions that are underway (Ulysses, WIND and SOHO) offer an opportunity for significant advances in our understanding of the corona and heliosphere. Through this interplay of observations and theory we can improve our understanding of the Sun. Our achievements thus far include progress modeling the large-scale structure of the solar corona, three-dimensional models of active region fields, development of emerging flux and current, formation and evolution of coronal loops, and coronal heating by current filaments. VanHoven, Gerard and Schnack, Dalton D. Goddard Space Flight Center NAG5-2257...
Download or read book Solar Prominences written by Jean-Claude Vial and published by Springer. This book was released on 2014-11-24 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents the latest research results on solar prominences, including new developments on e.g. chirality, fine structure, magnetism, diagnostic tools and relevant solar plasma physics. In 1875 solar prominences, as seen out of the solar limb, were described by P.A. Secchi in his book Le Soleil as "gigantic pink or peach-flower coloured flames". The development of spectroscopy, coronagraphy and polarimetry brought tremendous observational advances in the twentieth century. The authors present and discuss exciting new challenges (resulting from observations made by space and ground-based telescopes in the 1990s and the first decade of the 21st century) concerning the diagnostics of prominences, their formation, their life time and their eruption along with their impact in the heliosphere (including the Earth). The book starts with a general introduction of the prominence “object” with some historical background on observations and instrumentation. In the next chapter, the various forms of prominences are described with a thorough attempt of classification. Their thermodynamic (and velocity) properties are then derived with emphasis on the methods (and their limits) used. This goes from the simplest optically thin case to the heavy radiative treatment of plasmas out of local thermodynamic equilibrium. The following chapters are devoted to the magnetic field measurements and indirect derivation. A new branch of diagnostic tools, the seismology, is presented along with some MHD basics. This allows to better understand the propagation of waves, the energy and force equilibria. Both small-scale and large-scale studies and their relationship are presented. The importance of the newly discovered cavities is stressed in the context of prominence destabilization. The issues of prominence formation and eruption, their connection with flares and Coronal Mass Ejections and their impact on the Earth are addressed on the basis of the latest results. Finally, an exciting new area of research is unveiled with the newly discovered evidence of similar manifestations in the Universe and their possible impact on the habitability of exoplanets. References to the basic physics (where necessary) are provided and the proposed web sites addresses will allow the reader to load exciting movies. The book is aimed at advanced students in astrophysics, post-graduates, solar physicists and more generally astrophysicists. Amateurs will enjoy the many new images which go with the text.
Download or read book Coronal Holes and High Speed Wind Streams written by Jack B. Zirker and published by . This book was released on 1977 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt:
