Download or read book Large Scale Velocity Fields and Small Scale Magnetic Fields During the Maximum of Solar Cycle 22 written by and published by . This book was released on 1992 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The key accomplishments from the research during FY 1991 were: (1) the finding by K. Harvey and P. Foukal that the photospheric network is the third significant component that accounts for observed variations in the total solar irradiance; (The first previously recognized component is the temporary decreases due to sunspots and the second is variation due to plage brightness.) (2) the K. Harvey results from studying magnetic flux over the solar cycle: (a) increases in the total magnetic flux by a factor of 4 to 5 from solar minimum to solar maximum with the variation from active regions flux (>25 Gauss) by more than a factor of 20 from cycle minimum to maximum while the variation from quiet sun fields (
Download or read book Studies of Solar Magnetic Fields During the Rise of Solar Cycle 22 written by and published by . This book was released on 1991 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: New information about the solar cycle and the changing magnetic fields includes: (1) Every solar cycle has a duration of 18-22 years even though the peak between successive cycles is approximately 11 years. This means that there are two solar cycles on the sun nearly all of the time; the exception is the few years preceeding solar maximum. (2) a large-scale velocity field was discovered around the perimeter of one of the major active regions that developed during the rise of the current solar cycle. If averaged over a several month interval, the velocity would be of the same order of magnitude as the velocity pattern of the torsional oscillation signal that varies systematically over the solar cycle. The newly discovered velocity pattern can be interpreted as either a severe contamination to the torsional oscillation signal or another way of observing the torsional oscillation velocity field. (3) Our analyses of small-scale magnetic fields on the quiet sun has shown that network magnetic fields are continuously being replaced by intranetwork magnetic fields. The replacement occurs when intranetwork magnetic fields collide with network magnetic fields; both polarities are observed to cancel each other at a mean rates of 10 to the 18th power Maxwells/hour. The non-cancelling components of the intranetwork magnetic field replace the cancelled components of the network. No net long-term increases or decreases in magnetic flux occur as a consequence of these processes.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar Magnetic Fields written by Manfred Schüssler and published by Cambridge University Press. This book was released on 1994-06-16 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: How are large-scale magnetic fields generated in the Sun in self-excited dynamo processes? And how are magnetic structures spontaneously formed in the Sun and how do they interact with the convective flows, storage and release of magnetic energy? These are just several of the fundamental questions answered in this timely review of our understanding of solar magnetic fields. This volume collects together review articles and research papers from an international conference, held in Freiburg, Germany, dedicated to the study of magnetic fields in the Sun. From large-scale patterns and global dynamo action to tiny flux tubes, from the overshoot layer below the convection zone up to the corona, and from instrumental problems and theoretical methods to the latest ground-based and satellite observations, this volume provides an essential review of our knowledge to date for graduate students and researchers.
Download or read book Global Evolution of Magnetic Fields in the Photosphere of the Sun During Cycles 20 23 written by Reto Knaack and published by Cuvillier Verlag. This book was released on 2005 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Magnetoconvection written by N. O. Weiss and published by Cambridge University Press. This book was released on 2014-10-30 with total page 411 pages. Available in PDF, EPUB and Kindle. Book excerpt: Leading experts present the current state of knowledge of the subject of magnetoconvection from the viewpoint of applied mathematics.
Download or read book Basic Mechanisms of Solar Activity written by V. Bumba and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our first attempt to organize a Symposium on solar activity was made at the lAO General Assembly in Brighton 1970. There, at the session of Commission 10, we proposed to organize a Symposium which would stress the observational aspects of solar activity. It was our hope that such a Symposium might stimulate studies of those important problems in solar physics which for a long time had been neglected in overall scientific discussion. Although a provisional date for the Symposium was then decided, it did not take place to avoid overlapping with other lAO activities. At the session of Commission 10 in Sydney -on the occasion of the XVth lAO General Assembly in 1973 -we repeated our proposal and forwarded the invitation of the Czechoslovak Academy of Sciences to organize the Symposium in Prague. Both were accepted. During the discussions about the programme of the Symposium -enthusiastically promoted by the late president of Commission 10, Prof. K. O. Kiepenheuer -it was decided to change slightly its subject. The theoreti cal problems were stressed and the majority of the Scientific Organizing Committee agreed not to deal with short-lived phenomena of the solar activity or with individual active regions. Symposium No. 71 was held in Prague from August 25 to August 29, 1975. Its Organizing Committee consisted of V. Bumba (Chairman), W. Deinzer, R. G. Giovanelli, R. Howard, K. O. Kiepenheuer, M. Kopecky, T. Krause, M. Kuperus, G.
Download or read book Advances in Nonlinear Dynamos written by Antonio Ferriz-Mas and published by CRC Press. This book was released on 2019-04-24 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonlinear dynamo theory is central to understanding the magnetic structures of planets, stars and galaxies. In chapters contributed by some of the leading scientists in the field, this text explores some of the recent advances in the field. Both kinetic and dynamic approaches to the subject are considered, including fast dynamos, topological methods in dynamo theory, physics of the solar cycle and the fundamentals of mean field dynamo. Advances in Nonlinear Dynamos is ideal for graduate students and researchers in theoretical astrophysics and applied mathematics, particularly those interested in cosmic magnetism and related topics, such as turbulence, convection, and more general nonlinear physics.
Download or read book Literature 1983 Part 1 written by S. Böhme and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 825 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 33 records literature published in 1983 and received before August 1, 1983. 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 organizations, observatories, and publishers which provide us with complimentary copies of their publications. 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, and Ms. Sylvia Matyssek. Mr. Martin Schlotelburg and Mr. Ulrich Uberall supported our task by careful proofreading. It is a pleasure to thank them all for their encouragement. Heidelberg, September 1983 The Editors Contents Introduction . . . . . . . . . . . . 1 Concordance Relation: ICSU-AB-AAA 3 Abbreviations 10 Periodicals, Proceedings, Books, Activities 001 Periodicals . . . . . . . . . . . 15 002 Bibliographical Publications, Documentation, Catalogues, Atlases 47 003 Books ...... . 51 004 History of Astronomy 58 005 Biography . . 64 006 Personal Notes 65 007 Obituaries . . .
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 1396 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Literature 1997 Part 1 written by Astronomisches Rechen-InstitutARI and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1746 pages. Available in PDF, EPUB and Kindle. Book excerpt: Astronomy and Astrophysics Abstracts is devoted to the recording, summarizing and indexing of astronomical publications throughout the world. Two volumes are scheduled to appear per year. Volume 67 records 10,903 papers covering besides the classical fields of astronomy and astrophysics such matters as space flights related to astronomy, lunar and planetary probes and satellites, meteorites and interplanetary matter, X rays and cosmic rays, quasars and pulsars. The abstracts are classified under more than one hundred subject categories thus permitting quick surveying of the bulk of material published on the same topic within six months. For instance, this volume records 119 papers on minor planets, 155 papers on supernovae, and 554 papers on cosmology.
Download or read book Physics at the Frontiers of the Standard Model written by Nguyen van Hiêu and published by Atlantica Séguier Frontières. This book was released on 1996 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sunspots Theory and Observations written by J.H. Thomas and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains the invited papers presented at the NATO Advanced Research Workshop on the Theory of Sunspots, held in Cambridge, England, 22-27 September 1991. The idea of holding this Workshop first arose during the Solar Optical Telescope work shop on Theoretical Problems in High-Resolution Solar Physics in Munich in 1985. At that meeting, separate discussion groups were formed to consider specific topics in solar physics. The discussion group on sunspots recommended that there be a meeting devoted to theoretical problems associated with sunspots, the motivation being the consensus that theory seemed to lag behind the observational evidence in our quest for a satisfactory un derstanding of the physics of sunspots. This recommendation was warmly received and the two of us were designated to organize the Workshop. Although the Workshop eventually took place later than originally envisioned, the de lay turned out to be fortunate and the timing of the Workshop was ideal for a number of reasons. There have been remarkable improvements in high-resolution observations of sunspots in the past few years, and many important new observational results were pre sented for the first time at this Workshop (by groups working at the Lockheed Palo Alto Research Laboratories, the Swedish and German telescopes in the Canary Islands, and the V. S. National Solar Observatory). Vector magnetographs and Stokes polarimetry have at last given us reliable measurements of the vector magnetic fields in sunspots.
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1991 with total page 1258 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solar Photosphere Structure Convection and Magnetic Fields written by Jan Olof Stenflo and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar and stellar photospheres constitute the layers most accessible to observations, forming the interface between the interior and the outside of the stars. The solar atmosphere is a rich physics laboratory, in which the whole spectrum of radiative, dynamical, and magnetic processes that tranfer energy into space can be observed. As the fundamental processes take place on very small spatial scales, we need high· resolution observations to explore them. On the other hand the small-scale processes act together to form global properties of the sun, which have their origins in the solar interior. The rapid advances in observational techniques and theoreticallllodelling over the past decade made it very timely to bring together scientists from east and west to the first lAU Symposium on this topic. The physics of the photosphere involves complicated interactions between magnetic fields, convection, waves, and radiation. During the past decade our understanding of these gener ally small-scale structures and processes has been dramatically advanced. New instrumen tations, on ground and in space, have given us new means to study the granular convection. Diagnostic methods in Stokes polarimetry have allowed us to go beyond the limitations of spatial resolution to explore the structure and dynamics of the subarcsec magnetic struc tures. Extensive numerical simulations of the interaction between convection and magnetic fields using powerful supercomputers are providing deepened physical insight. Granulation, magnetic fields, and dynamo processes are being explored in the photospheres of other stars, guided by our improved understanding of the solar photosphere.
Download or read book Literature 1989 Part 1 written by Astronomisches Rechen-Institut and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 1433 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: "Astronomy and Astrophysics Abstracts has appeared in semi-annual volumes since 1969 and it has already become one of the fundemental publications in the fields of astronomy, astrophysics and neighbouring sciences. It is the most important English-language abstracting journal in the mentioned branches. ...The abstracts 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." Space Science Review# "Dividing the whole field plus related subjects into 108 categories, each work is numbered and most are accompanied by brief abstracts. Fairly comprehensive cross-referencing links relevant papers to more than one category, and exhaustive author and subject indices are to be found at the back, making the catalogues easy to use. The series appears to be so complete in its coverage and always less than a year out of date that I shall certainly have to make a little more space on those shelves for future volumes." The Observatory Magazine#
Download or read book Physics of the Sun written by P.A. Sturrock and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume, together with its two companion volumes, originated in a study commis sioned by the United States National Academy of Sciences on behalf of the National Aeronautics and Space Administration. A committee composed of Tom Holzer, Dimitri Mihalas, Roger Ulrich and myself was asked to prepare a comprehensive review of current knowledge concerning the physics of the Sun. We were fortunate in being able to persuade many distinguished scientists to gather their forces for the preparation of 21 separate chapters covering not only solar physics but also relevant areas of astrophysics and solar-terrestrial relations. It proved necessary to divide the chapters into three separate volumes that cover three different aspects of solar physics. Volumes II and III are concerned with 'The Solar Atmosphere' and with 'Astrophysics and Solar-Terrestrial Relations'. This volume is devoted to 'The Solar Interior', except that the volume begins with one chapter reviewing the contents of all three volumes. Our study of the solar interior includes a review of nuclear, atomic, radiative, hydrodynamic and hydromagnetic processes, together with reviews of three areas of active current investigation: the dynamo mechanism, internal rotation and magnetic fields, and oscillations. The last topic, in particular, has emerged in recent years as one of the most exciting areas of solar research.
