Energy Release And Particle Acceleration At The Sun And In The Heliosphere

This is an introduction to the physics of space plasmas and its applications to current research into heliospheric and magnetospheric physics. To help the beginner, this book uses a new approach, interweaving concepts and observations to give basic explanations of the phenomena, to show limitations in these explanations, and to identify fundamental questions. 170 illus.

This volume helps the reader to understand the ways and means of how dynamical phenomena are generated at the Sun, how they travel through the Heliosphere, and how they affect Earth. It provides an integrated account of the three principal chains of events all the way from the Sun to Earth: the normal solar wind, coronal mass ejections, and solar energetic particles.

All papers have been peer-reviewed. Our star is a very effective particle accelerator. Energies up to GeVs have been observed in Solar energetic particle events. These events are often associated with solar flares and/or Coronal Mass Ejections. Understanding how particles are accelerated in these phenomena has been an outstanding problem in space plasma physics for a long time. Part of the reason is its practical (e.g. Space weather) and fundamental (cosmic ray origin) importance. In this conference we review recent progresses on this problem, with a balance between observations, theories and numerical simulations. Specific topics include 1) particle acceleration at flare site, 2) turbulence properties of the solar wind, 3) particle acceleration and transport in the inner heliosphere, 4) particle acceleration at the termination shock and heliosheath, and 5) particle acceleration at supernova remnant shocks.

Energetic particles are accelerated in rich profusion at sites throughout the heliosphere. They come from solar flares in the low corona, from shock waves driven outward by coronal mass ejections (CMEs), from planetary magnetospheres and bow shocks. They come from corotating interaction regions (CIRs) produced by high-speed streams in the solar wind, and from the heliospheric termination shock at the outer edge of the heliospheric cavity. We sample all these populations near Earth, but can distinguish them readily by their element and isotope abundances, ionization states, energy spectra, angular distributions and time behavior. Remote spacecraft have probed the spatial distributions of the particles and examined new sources in situ. Most acceleration sources can be "seen" only by direct observation of the particles; few photons are produced at these sites. Wave-particle interactions are an essential feature in acceleration sources and, for shock acceleration, new evidence of energetic-proton-generated waves has come from abundance variations and from local cross-field scattering. Element abundances often tell us the physics the source plasma itself, prior to acceleration. By comparing different populations, we learn more about the sources, and about the physics of acceleration and transport, than we can possibly learn from one source alone.

Physics of the Inner Heliosphere gives for the first time a comprehensive and complete summary of our knowledge of the inner solar system. Using data collected over more than 11 years by the HELIOS twin solar probes, one of the most successful ventures in unmanned space exploration, the authors have compiled six extensive reviews of the physical processes of the inner heliosphere and their relation to the solar atmosphere. Researchers and advanced students in space and plasma physics, astronomy, and solar physics will be surprised to see just how closely the heliosphere is tied to, and how sensitively it depends on, the sun. Volume 2 deals with particles, waves, and turbulence, with chapters on: - magnetic clouds - interplanetary clouds - the solar wind plasma and MHD turbulence - waves and instabilities - energetic particles in the inner solar system

9 MHDTurbulence in the Heliosphere: Evolution and Intermittency 253 Bruno Bavassano, Roberto Bruno and Vincenzo Carbone 1 Introduction 254 2 MHD Turbulence Evolution 255 2. 1 Ecliptic Turbulence 256 2. 2 Polar Turbulence 258 2. 3 Conclusions on Turbulence Evolution 263 3 Intermittency 264 3. 1 Probability Distribution Functions of Fluctuations and Self-similarity 269 3. 2 Radial Evolution of Intermittency 271 3. 3 Identifying Intermittent Events 273 3. 4 Conclusions on Intermittency 277 10 283 Waves and Turbulence in the Solar Corona Eckart Marsch 1 Introduction 284 2 Coronal Magnetic Field Structures 284 3 Magnetic Network Activity and Coronal Heating 287 4 Waves and Flows in Loops and Funnels 290 5 Magnetohydrodynamic Waves and Flux Tube Oscillations 293 5. 1 Observation and Theory 293 5. 2 Oscillations of Thin Flux Tubes 295 5. 3 Wave Amplitudes Versus Height from Numerical Mod- ~ 2~ 5. 4 A Standing Slow Magnetoacoustic Wave 299 6 Plasma Waves and Heating of Particles 301 7 Generation, Transfer and Dissipation of Coronal Turbulence 303 7. 1 Generation of Magnetohydrodynamic Waves 303 7. 2 Wave Energy Transfer and Turbulent Cascade 304 7. 3 Wave Dissipation in the Kinetic Domain 307 7. 4 Origin and Generation of Coronal High-Frequency Waves 308 7.

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.

Over the last decade we entered a new exploration phase of solar flare physics, equipped with powerful spacecraft such as Yohkoh, SoHO, and TRACE that pro vide us detail-rich and high-resolution images of solar flares in soft X-rays, hard X -rays, and extreme-ultraviolet wavelengths. Moreover, the large-area and high sensitivity detectors on the Compton GRO spacecraft recorded an unprecedented number of high-energy photons from solar flares that surpasses all detected high energy sources taken together from the rest of the universe, for which CGRO was mainly designed to explore. However, morphological descriptions of these beau tiful pictures and statistical catalogs of these huge archives of solar data would not convey us much understanding of the underlying physics, if we would not set out to quantify physical parameters from these data and would not subject these measurements to theoretical models. Historically, there has always been an unsatisfactory gap between traditional astronomy that dutifully describes the mor phology of observations, and the newer approach of astrophysics, which starts with physical concepts from first principles and analyzes astronomical data with the goal to confirm or disprove theoretical models. In this review we attempt to bridge this yawning gap and aim to present the recent developments in solar flare high-energy physics from a physical point of view, structuring the observations and analysis results according to physical processes, such as particle acceleration, propagation, energy loss, kinematics, and radiation signatures.

Heliophysics is a fast-developing scientific discipline that integrates studies of the Sun's variability, the surrounding heliosphere, and the environment and climate of planets. The Sun is a magnetically variable star and for planets with intrinsic magnetic fields, planets with atmospheres, or planets like Earth with both, there are profound consequences. This 2010 volume, the second in this series of three heliophysics texts, integrates the many aspects of space storms and the energetic radiation associated with them - from causes on the Sun to effects in planetary environments. It reviews the physical processes in solar flares and coronal mass ejections, interplanetary shocks, and particle acceleration and transport, and considers many space weather responses in geospace. In addition to its utility as a textbook, it also constitutes a foundational reference for researchers in fields from heliophysics to climate science. Additional online resources, including lecture presentations and other teaching materials, are available at www.cambridge.org/9780521760515.