Solar Energetic Particles


Book Description

This concise primer introduces the non-specialist reader to the physics of solar energetic particles (SEP) and systematically reviews the evidence for the two main mechanisms which lead to the so-called impulsive and gradual SEP events. More specifically, the timing of the onsets, the longitude distributions, the high-energy spectral shapes, the correlations with other solar phenomena (e.g. coronal mass ejections), as well as the all-important elemental and isotopic abundances of SEPs are investigated. Impulsive SEP events are related to magnetic reconnection in solar flares and jets. The concept of shock acceleration by scattering on self-amplified Alfvén waves is introduced, as is the evidence of reacceleration of impulsive-SEP material in the seed population accessed by the shocks in gradual events. The text then develops processes of transport of ions out to an observer. Finally, a new technique to determine the source plasma temperature in both impulsive and gradual events is demonstrated. Last but not least the role of SEP events as a radiation hazard in space is mentioned and a short discussion of the nature of the main particle telescope designs that have contributed to most of the SEP measurements is given.




Plasma Physics of the Local Cosmos


Book Description

Solar and space physics is the study of solar system phenomena that occur in the plasma state. Examples include sunspots, the solar wind, planetary magnetospheres, radiation belts, and the aurora. While each is a distinct phenomenon, there are commonalities among them. To help define and systematize these universal aspects of the field of space physics, the National Research Council was asked by NASA's Office of Space Science to provide a scientific assessment and strategy for the study of magnetized plasmas in the solar system. This report presents that assessment. It covers a number of important research goals for solar and space physics. The report is complementary to the NRC report, The Sun to the Earthâ€"and Beyond: A Decadal Research Strategy for Solar and Space Physics, which presents priorities and strategies for future program activities.




Particle Acceleration and Transport in the Heliosphere and Beyond


Book Description

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.




Solar Particle Radiation Storms Forecasting and Analysis


Book Description

Solar energetic particles (SEPs) emitted from the Sun are a major space weather hazard motivating the development of predictive capabilities. This book presents the results and findings of the HESPERIA (High Energy Solar Particle Events forecasting and Analysis) project of the EU HORIZON 2020 programme. It discusses the forecasting operational tools developed within the project, and presents progress to SEP research contributed by HESPERIA both from the observational as well as the SEP modelling perspective. Using multi-frequency observational data and simulations HESPERIA investigated the chain of processes from particle acceleration in the corona, particle transport in the magnetically complex corona and interplanetary space, to the detection near 1 AU. The book also elaborates on the unique software that has been constructed for inverting observations of relativistic SEPs to physical parameters that can be compared with space-borne measurements at lower energies. Introductory and pedagogical material included in the book make it accessible to students at graduate level and will be useful as background material for Space Physics and Space Weather courses with emphasis on Solar Energetic Particle Event Forecasting and Analysis. This work was published by Saint Philip Street Press pursuant to a Creative Commons license permitting commercial use. All rights not granted by the work's license are retained by the author or authors.







The Sun to the Earth â¬" and Beyond


Book Description

This volume, The Sun to the Earth-and Beyond: Panel Reports, is a compilation of the reports from five National Research Council (NRC) panels convened as part of a survey in solar and space physics for the period 2003-2013. The NRC's Space Studies Board and its Committee on Solar and Space Physics organized the study. Overall direction for the survey was provided by the Solar and Space Physics Survey Committee, whose report, The Sun to the Earth-and Beyond: A Decadal Research Strategy in Solar and Space Physics, was delivered to the study sponsors in prepublication format in August 2002. The final version of that report was published in June 2003. The panel reports provide both a detailed rationale for the survey committee's recommendations and an expansive view of the numerous opportunities that exist for a robust program of exploration in solar and space physics.




Solar Cosmic Rays


Book Description

It turned out to be really a rare and happy occasion that we know exact1y when and how a new branch of space physics was born, namely, a physics of solar cosmic rays. It happened on February 28 and March 7, 1942 when the fIrst "cosmic ray bursts" were recorded on the Earth, and the Sun was unambiguously identifIed for the fIrst time as the source of high-velocity 10 particles with energies up to > 10 eV. Just due to such a high energy these relativistic particles have been called "solar cosmic rays" (SCR), in distinction from the "true" cosmic rays of galactic origin. Between 1942 and the beginning ofthe space era in 1957 only extremely high energy solar particle events could be occasionally recorded by cosmic ray ground-Ievel detectors and balloon borne sensors. Since then the detection techniques varied considerably and the study of SCR turned into essential part of solar and solar-terrestrial physics.




Energetic Particles in the Heliosphere


Book Description

This monograph traces the development of our understanding of how and where energetic particles are accelerated in the heliosphere and how they may reach the Earth. Detailed data sets are presented which address these topics. The bulk of the observations are from spacecraft in or near the ecliptic plane. It is timely to present this subject now that Voyager-1 has entered the true interstellar medium. Since it seems unlikely that there will be a follow-on to the Voyager programme any time soon, the data we already have regarding the outer heliosphere are not going to be enhanced for at least 40 years.




The Sun, the Solar Wind, and the Heliosphere


Book Description

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.