Download or read book Helioseismic Detections of Sunspot Regions written by Efstathios Ilonidis and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Sunspots are regions where strong magnetic fields emerge from the solar interior and where major eruptive events occur. Sunspot studies are needed to understand the generation and emergence of magnetic fields in the photosphere and monitor the solar magnetic activity. In this thesis, local helioseismology methods are used to detect and study sunspot regions on the far-side of the Sun, the photosphere, and the deep convection zone, before these magnetic regions become visible on the solar disc. One of the successes of helioseismology is the imaging of solar far-side magnetic regions. Helioseismic holography and time-distance technique are capable of detecting sunspot regions on the far side of the sun and provide useful warnings for space weather forecasts. These techniques employ acoustic waves that travel to the far side and return to the front side after multiple bounces in the photosphere. We explore the possibility of far-side imaging by the time-distance technique using three-skip acoustic signals. This method is first validated with use of numerical simulation data and then it is used to detect sunspot regions on the solar far side using SOHO/MDI observations. It is shown that if these maps are combined with maps of existing methods, the appearance of spurious signals is reduced. Sunspot observations in the photosphere show that the acoustic power inside a sunspot region is significantly reduced compared to the quiet Sun. The power deficit is due to three main groups of physical mechanisms: absorption, emissivity reduction, and local suppression. These effects are separated with a measurement scheme that utilizes one- and double-skip waves in sunspots and quiet-sun regions. Using a large sample of sunspots observed with SOHO/MDI, the coefficients of each mechanism are measured as functions of travel distance and their relative contribution to the total power reduction is determined as well. The methods and the results of this study will be utilized for the detection of emerging sunspot regions in the convection zone. Helioseismic methods can be used to detect and study the properties of sunspot regions not only on the solar far side and the photosphere but also in the deep solar interior. We develop a measurement procedure which is capable of detecting emerging sunspot regions at depths around 60,000 km and 1-2 days before the detected magnetic structures emerge to the surface. The detection is based on measurements of the acoustic phase travel-time perturbations with the time-distance helioseismology technique using SOHO/MDI, SDO/HMI, and GONG datasets. The travel-time anomalies are related with cross-covariance frequency perturbations that depend strongly on the acoustic frequency. The implications of these measurements to studies of magnetic flux emergence in the solar convection zone and the potential applications to space weather forecasts are discussed.
Download or read book Sunspot Umbral Spectra in the Regions 1925 to 2226 and 2392 to 3480 Cm 1 2 87 to 4 18 and 4 48 to 5 35 mu M written by Lloyd Wallace and published by . This book was released on 2002 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Solar Dynamics Observatory written by Phillip Chamberlin and published by Springer Science & Business Media. This book was released on 2012-05-05 with total page 405 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is dedicated to the Solar Dynamics Observatory (SDO), which was launched 11 February 2010. The articles focus on the spacecraft and its instruments: the Atmospheric Imaging Assembly (AIA), the Extreme Ultraviolet Variability Experiment (EVE), and the Helioseismic and Magnetic Imager (HMI). Articles within also describe calibration results and data processing pipelines that are critical to understanding the data and products, concluding with a description of the successful Education and Public Outreach activities. This book is geared towards anyone interested in using the unprecedented data from SDO, whether for fundamental heliophysics research, space weather modeling and forecasting, or educational purposes. Previously published in Solar Physics journal, Vol. 275/1-2, 2012. Selected articles in this book are published open access under a CC BY-NC 2.5 license at link.springer.com. For further details, please see the license information in the chapters.
Download or read book Helioseismic Diagnostics of Solar Convection and Activity written by Zdenek Svestka and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 565 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the recent advances in our understanding of solar convection and activity, and on new methods and results of helioseismic diagnostics. It provides a comprehensive overview of the current status of the field and presents new ideas and approaches.
Download or read book Solar Origins of Space Weather and Space Climate written by Irene González Hernández and published by Springer. This book was released on 2014-06-17 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents an overview of recent research on the original of solar phenomena that affect Earth’s technological systems. This topical issue is based on the presentations given at the 26th National Solar Observatory (NSO) Summer Workshop held at the National Solar Observatory/Sacramento Peak, New Mexico, USA from 30 April to 4 May 2012. This unique forum brought together experts in different areas of solar and space physics to help in developing a full picture of the origin of solar phenomena that affect Earth’s technological systems. The articles include theory, model and observation research on the origin of the solar activity and its cycle, as well as a discussion on how to incorporate the research into space-weather forecasting tools. This volume is aimed at graduate students and researchers active in solar physics and space science. Previously published in Solar Physics, Vol. 289/2, 2014.
Download or read book Helioseismology of Sunspots on the Detection of Subsurface Structure and Evolution written by Matthias Waidele and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Extraterrestrial Seismology written by Vincent C. H. Tong and published by Cambridge University Press. This book was released on 2015-06-25 with total page 467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismology is a highly effective tool for investigating the internal structure of the Earth. Similar techniques have also successfully been used to study other planetary bodies (planetary seismology), the Sun (helioseismology), and other stars (asteroseismology). Despite obvious differences between stars and planetary bodies, these disciplines share many similarities and together form a coherent field of scientific research. This unique book takes a transdisciplinary approach to seismology and seismic imaging, reviewing the most recent developments in these extraterrestrial contexts. With contributions from leading scientists, this timely volume systematically outlines the techniques used in observation, data processing, and modelling for asteroseismology, helioseismology, and planetary seismology, drawing comparisons with seismic methods used in geophysics. Important recent discoveries in each discipline are presented. With an emphasis on transcending the traditional boundaries of astronomy, solar, planetary and Earth sciences, this novel book is an invaluable resource and reference for undergraduates, postgraduates and academics.
Download or read book Sunspots and Their Effects written by Harlan True Stetson and published by Read Books Ltd. This book was released on 2013-05-31 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt: The near approach of another sunspot maximum with accompanying interest shown by the press and the general public gives the occasion for a book on sunspots. Very interesting book on the history and detection of sunspots and their possible effects on humankind. A must for anyone interested in how sunspots will affect the earth and human affairs and those that like to keep themselves informed of trends in science.
Download or read book Helioseismology Asteroseismology and MHD Connections written by Laurent Gizon and published by Springer Science & Business Media. This book was released on 2008-12-19 with total page 638 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection of papers offers a timely snapshot of helio- and asteroseismology in the era when SOHO/MDI instrument is about to be replaced by SDO/HMI and when the CoRoT space mission is yielding its first long-duration light curves of thousands of stars.
Download or read book Cartography of the Sun and the Stars written by Jean-Pierre Rozelot and published by Springer. This book was released on 2016-03-11 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mapping of the surface of stars requires diverse skills, analysis techniques and advanced modeling, i.e. the collaboration of scientists in various specialties. This volume gives insights into new techniques allowing for the first time to obtain resolved images of stars. It takes stock of what has been achieved so far in Chile, on the ESO VLTI instrument or, in the States, on the CHARA instrument. In recent times interferometry, combined with adaptive optics has allowed to reconstruct images of stars. Besides the Sun (of course) by now five stars have been resolved in detail. In addition to interferometry, this book highlights techniques used for mapping the surfaces of stars using photometry made by space observatories; Zeeman- and Doppler Imaging; mapping the surface element abundances via spectroscopy. This book will also take stock of the best images of the solar surface, made by connecting the differential rotation to the underlying physical parameters derived from helioseismology. Recent measurements of flattening of the solar surface by SDO showed that the Sun’s shape is linked to the rotation of the core. It is shown how such a result is generalizable to the stars.
Download or read book The Sun the Solar Wind and the Heliosphere written by Mari Paz Miralles and published by Springer Science & Business Media. This book was released on 2011-01-06 with total page 379 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume represents the state of the art of the science covered by the International Association of Geomagnetism and Aeronomy (IAGA) Division IV: Solar Wind and Interplanetary Field. It contains a collection of contributions by top experts addressing and reviewing a variety of topics included under the umbrella of the division. It covers subjects that extend from the interior of the Sun to the heliopause, and from the study of physical processes in the Sun and the solar wind plasma to space weather forecasts. The book is organized in 6 parts: the solar interior, the solar atmosphere, the heliosphere, heliophysical processes, radio emissions, and coordinated science in the Sun-Earth system. In addition, we highlight some of the results presented during the IAGA Division IV symposia in the 11th Scientific Assembly of IAGA in Sopron, Hungary, on 23-30 August 2009, which was planned simultaneously with this book.
Download or read book Physics of the Sun written by Dermott J. Mullan and published by CRC Press. This book was released on 2022-09-13 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: With an emphasis on numerical modelling, Physics of the Sun: A First Course presents a quantitative examination of the physical structure of the Sun and the conditions of its extended atmosphere. It gives step-by-step instructions for calculating the numerical values of various physical quantities in different regions of the Sun. Fully updated throughout, with the latest results in solar physics, this second edition covers a wide range of topics on the Sun and stellar astrophysics, including the structure of the Sun, solar radiation, the solar atmosphere, and Sun-space interactions. It explores how the physical conditions in the visible surface of the Sun are determined by the opacity of the material in the atmosphere. It also presents the empirical properties of convection in the Sun, discusses the physical conditions which must be satisfied for nuclear reactions to occur in the core, and describes how radiation transports energy from the core outwards. This text enables a practical appreciation of the physical models of solar processes. Numerical modelling problems and step-by-step instructions are featured throughout, to empower students to calculate, using their own codes, the interior structure of different parts of the Sun and the frequencies of p-modes and g-modes. They encourage a firm grasp of the numerical values of actual physical parameters as a function of radial location in the Sun. It is an ideal introduction to solar physics for advanced undergraduate and graduate students in physics and astronomy, in addition to research professionals looking to incorporate modelling into their practises. Extensive bibliographies at the end of each chapter enable the reader to explore the latest research articles in the field. Features: Fully updated with the latest results from the spacecraft Hinode, Stereo, Solar Dynamics Observatory (SDO), Interface Region Imaging Spectrograph (IRIS), and Parker Solar Probe Presents step-by-step explanations for calculating numerical models of the photosphere, convection zone, and radiative interior with exercises and simulation problems to test learning Describes the structure of polytropic spheres and the acoustic power in the Sun and the process of thermal conduction in different physical conditions
Download or read book Solar Physics Research Trends written by Pingzhi Wang and published by Nova Publishers. This book was released on 2008 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest results on solar-stellar research and the study of solar terrestrial physics. It includes all aspects of solar physics, ranging from the internal structure of the sun and its evolution, to outer corona and solar wind in interplanetary space.
Download or read book Solar Dynamics and Magnetism from the Interior to the Atmosphere written by Nagi N. Mansour and published by Springer Science & Business Media. This book was released on 2013-12-03 with total page 445 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses recent advances and new problems in the exploration of the Sun's interior structure, solar dynamics and dynamo, mechanisms of sunspot and active regions formation, sources of solar irradiance variations and links between the subsurface dynamics, flaring and CME activity. NASA's Solar Dynamics Observatory (SDO) mission has provided a large amount of new data on solar dynamics and magnetic activities during the rising phase of the current and highly unusual solar cycle. These data are complemented by the continuing SOHO mission and by ground-based observatories that include the GONG helioseismology network and the New Solar Telescope. Also, the observations are supported by realistic numerical simulations on supercomputers. This unprecedented amount of data provides a unique opportunity for multi-instrument investigations that address fundamental problems of the origin of solar magnetic activity at various spatial and temporal scales. This book demonstrates that the synergy of high-resolution multi-wavelength observations and simulations is a key to uncovering the long-standing puzzles of solar magnetism and dynamics. This volume is aimed at researchers and graduate students active in solar physics and space science. Originally published in Solar Physics journal, Vol. 287/1-2, 2013.
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 2021-04-12 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 The Solar Activity Cycle written by André Balogh and published by Springer. This book was released on 2015-04-16 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: A collection of papers edited by four experts in the field, this book sets out to describe the way solar activity is manifested in observations of the solar interior, the photosphere, the chromosphere, the corona and the heliosphere. The 11-year solar activity cycle, more generally known as the sunspot cycle, is a fundamental property of the Sun. This phenomenon is the generation and evolution of magnetic fields in the Sun’s convection zone, the photosphere. It is only by the careful enumeration and description of the phenomena and their variations that one can clarify their interdependences. The sunspot cycle has been tracked back about four centuries, and it has been recognized that to make this data set a really useful tool in understanding how the activity cycle works and how it can be predicted, a very careful and detailed effort is needed to generate sunspot numbers. This book deals with this topic, together with several others that present related phenomena that all indicate the physical processes that take place in the Sun and its exterior environment. The reviews in the book also present the latest theoretical and modelling studies that attempt to explain the activity cycle. It remains true, as has been shown in the unexpected characteristics of the first two solar cycles in the 21st century, that predictability remains a serious challenge. Nevertheless, the highly expert and detailed reviews in this book, using the very best solar observations from both ground- and space based telescopes, provide the best possible report on what is known and what is yet to be discovered. Originally published in Space Science Reviews, Vol 186, Issues 1-4, 2014.
Download or read book Advances in Geosciences written by Marc Duldig and published by World Scientific. This book was released on 2010 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: This invaluable volume set of Advances in Geosciences continues the excellent tradition of the Asia-Oceania scientific community in providing the most up-to-date research results on a wide range of geosciences and environmental science. This information will be vital to the understanding the effects of climate change, extreme weathers on the most populated region and fastest moving economies in the world. Besides reviews, these volumes contain original papers from many prestigious research institutions which are doing cutting edge study in atmospheric physics, hydrological science and water resource, ocean science and coastal study, planetary exploration and solar system science, seismology, tsunamis, upper atmospheric physics and space science.
