Download or read book Structures and Heating Mechanisms of the Solar Corona written by Hirohasa Hara and published by . This book was released on 1996 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the contents of the thesis seem to cover a variety of topics in solar physics, there is a key phrase which connects. That is Structures and heating of the solar corona. This present thesis work is a starting point for the author to study formation processes of the solar corona and the magnetic activity cycle of the Sun. Two instruments are used in the present study. One is the soft X-ray telescope (SXT) aboard Yohkoh launched in August 1991 by the Institute of space and astronautical science (ISAS). Although the principal purpose of the Yohkoh mission is to understand solar flares, SXT can observe many types of structure in the corona from active regions to coronal holes, as well as flares. The other is a ground-based coronagraph with a high-dispersion spectrograph at the Norikura solar observatory (NSO) of the National astronomical observatory ( NAO) Japan.

Download or read book Mechanisms of Chromospheric and Coronal Heating written by Peter Ulmschneider and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 663 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the great problems of astrophysics is the unanswered question about the origin and mechanism of chromospheric and coronal heating. Just how these outer stellar envelopes are heated is of fundamental importance, since all stars have hot chromospheric and coronal shells where the temperature rises to millions of degrees, comparable to the temperatures in the stars' cores. Here for the first time is a comprehensive inventory of the proposed chromospheric and coronal heating theories. The proposed heating processes are critically compared, and the observational evidence for the various mechanisms is reviewed. This is essential reading for all those working in such fields as stellar activity, radio and XUV emission, rotation, and mass loss, for whom a detailed and consistent presentation of our knowledge of chromospheric and coronal heating mechanisms is urgently needed.

Download or read book Physics of the Solar Corona written by Markus Aschwanden and published by Springer Science & Business Media. This book was released on 2004-09 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt: A thorough introduction to solar physics based on recent spacecraft observations. The author introduces the solar corona and sets it in the context of basic plasma physics before moving on to discuss plasma instabilities and plasma heating processes. The latest results on coronal heating and radiation are presented. Spectacular phenomena such as solar flares and coronal mass ejections are described in detail, together with their potential effects on the Earth.

Download or read book Space Physics and Aeronomy Solar Physics and Solar Wind written by Nour E. Raouafi and published by John Wiley & Sons. This book was released on 2021-05-11 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive view of our Sun at the start of a new era in solar and heliospheric physics Humans have been observing and studying our Sun for centuries, yet much is still unknown about the processes that drive its behavior. Thanks to a new generation of space missions and ground telescopes, we are poised to dramatically increase our understanding of the Sun and its environment. Solar Physics and Solar Wind explores advances in solar and heliospheric research over recent decades, as well as the challenges that remain. This comprehensive reference work covers the solar interior, magnetism and radiation, plasma heating and acceleration, the sun's atmosphere, and solar activity. Volume highlights include: Explanations for processes in the solar interior New insights on the solar wind The challenges of measuring the Sun's magnetic field and its radiative output Description of solar atmospheric phenomena such as spicules and jets New developments in understanding flares and coronal mass ejections Ongoing research into how the solar corona is heated 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. Find out more about the Space Physics and Aeronomy collection in this Q&A with the Editors in Chief

Download or read book Magnetic Origins of Cool Plasma in the Sun s Corona written by Emily Irene Mason and published by . This book was released on 2020 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Much of solar physics research focuses on two questions: how the corona's temperature becomes hundreds of times hotter than the surface, and how the slow solar wind forms. Among the most fascinating phenomena produced by coronal heating is coronal rain, in which plasma undergoes rapid cooling (from roughly 106 to 103 K), condenses, and falls to the surface. One proposed rain origin theory, thermal nonequilibrium (TNE), posits a height restriction in coronal heating. By studying condensations, physicists hope to better understand coronal heating.Solar wind is often subdivided into fast and slow wind. The former originates in coronal hole regions; slow wind's source, however, is still under debate. One leading theory postulates that it comes from coronal hole boundaries, where magnetic field lines frequently reconnect.This dissertation investigates the origins and dynamics of coronal rain via study of recently-discovered structures called raining null-point topologies, or RNPTs. RNPTs - the first identification and characterization of which comprise part of this work - are decaying active regions situated near coronal hole boundaries, between 50-150 Mm in height. They are host to long periods of continuous coronal rain formation, and provide insight into coronal heating, slow solar wind origins, and coronal dynamics. This dissertation poses the following science questions:1. What specific mechanisms power the coronal rain and dynamics in RNPTs?2. What do these structures and the rain they contain tell us about the fundamental mechanisms of coronal heating?3. What do these structures and the rain they contain tell us about the fundamental origins and mechanisms of the slow solar wind?First, we focus on identifying and analyzing RNPTs' observational characteristics. We process and analyze RNPT data using both the Solar Dynamics Observatory Atmospheric Imaging Assembly and the Helioseismic and Magnetic Imager. Potential field source-surface extrapolations that model the magnetic field in the corona aid in the interpretation of the structures' topology. Next, we conduct a heating regime parameter study of 1D hydrodynamic simulations using the HYDrodynamic and RADiation Code (HYDRAD). This models a single flux tube that approaches the null, producing large asymmetry and a drastic cross-sectional expansion near the loop apex.Results indicate that RNPTs experience two rain-forming mechanisms, thermal nonequilibrium and interchange reconnection. The interchange reconnection is posited to power much of the early bursts of coronal rain, which constitutes a new rain-formation mechanism and allows for plasma from closed loops to escape into the slow solar wind. Observations also show evidence of partial condensations, which condense but do not fully cool. The results of the modeling study imply that heating scale heights in RNPTs must be much lower than in symmetric loops in order to support the observed TNE cycles. They also show that the apex's large expansion introduces a reverse siphon flow and suppresses condensations. The simulations show significant decreases in density near the apex and warm condensations, in good agreement with the observations. This two- pronged approach produces a broad yet detailed study of RNPT dynamics.

Download or read book Physics of the Solar Corona written by Constantin J. Macris and published by . This book was released on 1971 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 2012-12-06 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 The Structure and Heating of the Chromosphere corona Transition Region written by Ronald Lee Moore and published by . This book was released on 1972 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: A broad endeavor of solar physics is to determine from the observed radiation the structure of the solar atmosphere and the nature of the energy balance which this structure implies. A basic feature of the solar atmosphere which is still not well understood is the chromosphere-corona transition region in which, in a height of a few thousand kilometers, the temperature increases from about 10,000 degrees K at the top of the chromosphere to about 1,000,000 degrees K at the bottom of the corona. The problem investigated in this dissertation is that of the structure and heating (or energy balance) of the transition region and the role of the transition region in the structure and heating of the atmosphere as a whole. (Author).

Download or read book Multi Wavelength Observations of Coronal Structure and Dynamics written by Penny Martens and published by Elsevier. This book was released on 2002-10-21 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: These are the Proceedings of the Yohkoh 10th Anniversary Meeting, a COSPAR Colloquium held in Kona, Hawaii, USA, on January 20-24, 2002. The title of the meeting was Multi-Wavelength Observations of Coronal Structure and Dynamics. In these proceedings the many and varied advances of the dynamics solar atmosphere in the past ten years of observations by Yohkoh have been reviewed.

Download or read book The Solar Corona written by Leon Golub and published by Cambridge University Press. This book was released on 2010 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: Second edition graduate level textbook giving an up-to-date treatment of our understanding of the solar corona.

Download or read book Literature 1991 Part 2 written by Astronomisches Rechen-Institut and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 1592 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Astronomy and Astrophysics Abstracts" appearing twice a year has become oneof the fundamental publications in the fields of astronomy, astrophysics andneighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. The abstrats are classified under more than a hundred subject categories, thus permitting a quick survey of the whole extended material. The AAA is a valuable and important publication for all students and scientists working in the fields of astronomy and related sciences. As such it represents a necessary ingredient of any astronomical library all over the world.

Download or read book The Physics of the Solar Corona and Transition Region written by Oddbjorn Engvold and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar Physics publishes up to two Topical Issues per year that focus on areas of especially vigorous and active research. The present Topical Issue contains papers of recent results on the solar corona, as well as on the transition region and low solar wind. The majority of these papers, which were all refereed in accordance with the standards of Solar Physics, were presented in August 1999 at a workshop held in Monterey, California. The authors were offered the opportunity to present relevant parts of their contributions on an accompanying CD ROM of this Topical Issue. The Sun's magnetic field is responsible for the spectacularly dynamic and intri cate phenomenon that we call the corona. The past decade has seen an enormous increase in our understanding of this part of the solar outer atmosphere, both as a result of observations and because of rapid advances in numerical studies. The Yohkoh satellite has observed the Sun now for over eight years, producing spectac ular sequences of images that convey the complexity of the corona. The imaging and spectroscopic instruments on SOHO have added information on the cooler part of the corona. And since April of 1998 TRACE has given us very high resolution images of the 1-2 MK corona, at cadences that allow detailed observations of field oscillations, loop evolution, mass ejecta, etc.

Download or read book Heating and Energetics of the Solar Corona and Solar Wind written by COSPAR. Scientific Assembly and published by . This book was released on 2002 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solar Coronal Structure Study written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-25 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this investigation is to study the physics of the solar corona through the analysis of the EUV and UV data produced by two flights (12 May 1992 and 25 April 1994) of the Lockheed Solar Plasma Diagnostics Experiment (SPDE) sounding rocket payload, in combination with Yohkoh and ground-based data. Each rocket flight produced both spectral and imaging data. These joint datasets are useful for understanding the physical state of various features in the solar atmosphere at different heights ranging from the photosphere to the corona at the time of the, rocket flights, which took place during the declining phase of a solar cycle, 2-4 years before the minimum. The investigation is narrowly focused on comparing the physics of small- and medium-scale strong-field structures with that of large-scale, weak fields. As we close th is investigation, we have to recall that our present position in the understanding of basic solar physics problems (such as coronal heating) is much different from that in 1995 (when we proposed this investigation), due largely to the great success of SOHO and TRACE. In other words, several topics and techniques we proposed can now be better realized with data from these missions. For this reason, at some point of our work, we started concentrating on the 1992 data, which are more unique and have more supporting data. As a result, we discontinued the investigation on small-scale structures, i.e., bright points, since high-resolution TRACE images have addressed more important physics than SPDE EUV images could do. In the final year, we still spent long time calibrating the 1992 data. The work was complicated because of the old-fashioned film, which had problems not encountered with more modern CCD detectors. After our considerable effort on calibration, we were able to focus on several scientific topics, relying heavily on the SPDE UV images. They include the relation between filaments and filament channels, the identification of hot loop

Download or read book High Resolution Studies of the Structure of the Solar Atmosphere written by and published by . This book was released on 1996 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our approach has focused on exploring the physical characteristics of the coronal heating mechanisms, as manifested in coronal holes, quiet regions and active regions, using different data sets, data analysis techniques and image processing tools. The main results from these studies can be summarized as follows: (1) Temperature inferences in different coronal structures rely on the spectral lines used. Their judicious choice is particularly crucial for reliable inferences in coronal holes. (2) Limits on the helium abundance in the inner corona can be inferred from knowledge of the temperature and density, and their gradients in that region. (3) There exists a characteristic spatial separation of 10"-15" between the substructures within coronal holes, that is independent of the temperature of the emitting plasma, or the large scale overlying magnetic field. (4) Different temperature plasmas coexist at coronal heights regardless of the overlying large scale structure, such as active regions, quiet regions or coronal holes, and within these structures. (5) The spatial distribution of the temporal variability of the coronal emission has a very distinct temperature dependence, with a peak at 100,000 K, and is independent of the structure of the overlying large scale magnetic field. (6) In regard to some of the most spectacular forms of dynamic magnetic events, namely corona mass ejections, nonthermal emission as manifested in the form of type I noise storms observed at 90 cm, can serve as predictors for the occurrence of these events.

Download or read book Literature 1985 Part 1 written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-12-11 with total page 1157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts aims to present a comprehensive documen tation of the literature concerning all aspects of astronomy, astrophysics, and their border fields. It is devoted to the recording, summarizing, and indexing of the relevant publications throughout the world. Astronomy and Astrophysics Abstracts is prepared by a special department of the Astronomisches Rechen-Institut under the auspices of the International Astronomical Union. Volume 39 records literature published in 1985 and received before August 15, 1985. Some older documents which we received late and which are not surveyed in earlier volumes are included too. We acknowledge with thanks contributions of our colleagues all over the world. We also express our gratitude to all organiza tions, observatories, and publishers which provide us with complimentary copies of their publications. On account of the introduction of an object index the scope of index information will be considerably enlarged beginning with this volume. In connection with the subject index an additional source to satisfy the needs of retrieval is opened up. Starting with Volume 33, all the recording, correction, and data processing work was done by means of computers. The recording was done by our technical staff members Ms. Helga Ballmann, Ms. Mona El-Choura, Ms. Monika Kohl, Ms. Sylvia Matyssek. Ms. Karin Burkhardt, Ms. Susanne Schlotelburg, and Mr. Stefan Wagner supported our task by careful proofreading. It is a pleasure to thank them all for their encouragement. Heidelberg, September 1985 The Editors Contents Introduction . . . . . . . . . . . .

Download or read book Solar Coronal Structures written by International Astronomical Union. Colloquium and published by Veda. This book was released on 1994 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: