Download or read book Solar Energetic Particles written by Donald V. Reames and published by Springer. This book was released on 2017-03-10 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Coronal Mass Ejections and Solar Energetic Particle Events written by and published by . This book was released on 1996 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We review the observations relating solar energetic particle (SEP) events to coronal mass ejections (CMEs). Nearly every gradual SEP event is associated with a fast (v> 400 km/s) CME, which is presumed to drive a coronal shock that accelerates the SEPs. Evidence supporting the contention that all SEP ions observed in large, gradual events are shock accelerated is reviewed. Evidence for shock acceleration of electrons is found to be more ambiguous. The following current questions in SEP/CME relationships are discussed: (1) SEP production by electric fields in post-flare loops; (2) the relationship of type II burst shocks and CME-driven shocks; (3) flare impulsive phase contributions to SEP events; and (4) the evidence for shock-accelerated (SA) events; and (5) progressively hardening X-ray spectra and SEP events.
Download or read book Radiation and the International Space Station written by National Research Council and published by National Academies Press. This book was released on 2000-03-25 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: A major objective of the International Space Station is learning how to cope with the inherent risks of human spaceflightâ€"how to live and work in space for extended periods. The construction of the station itself provides the first opportunity for doing so. Prominent among the challenges associated with ISS construction is the large amount of time that astronauts will be spending doing extravehicular activity (EVA), or "space walks." EVAs from the space shuttle have been extraordinarily successful, most notably the on-orbit repair of the Hubble Space Telescope. But the number of hours of EVA for ISS construction exceeds that of the Hubble repair mission by orders of magnitude. Furthermore, the ISS orbit has nearly twice the inclination to Earth's equator as Hubble's orbit, so it spends part of every 90-minute circumnavigation at high latitudes, where Earth's magnetic field is less effective at shielding impinging radiation. This means that astronauts sweeping through these regions will be considerably more vulnerable to dangerous doses of energetic particles from a sudden solar eruption. Radiation and the International Space Station estimates that the likelihood of having a potentially dangerous solar event during an EVA is indeed very high. This report recommends steps that can be taken immediately, and over the next several years, to provide adequate warning so that the astronauts can be directed to take protective cover inside the ISS or shuttle. The near-term actions include programmatic and operational ways to take advantage of the multiagency assets that currently monitor and forecast space weather, and ways to improve the in situ measurements and the predictive power of current models.
Download or read book Coronal Mass Ejections and Solar Particle Events in Solar Cycle 23 written by Christina Cohen and published by . This book was released on 2006 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characteristic Times of Gradual Solar Energetic Particle Events and Their Dependence on Associated Coronal Mass Ejection Properties written by and published by . This book was released on 2005 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: We use 20 MeV proton intensities from the EPACT instrument on Wind and coronal mass ejections (CMEs) from the LASCO coronagraph on SOHO observed during 1998-2002 to statistically determine three characteristic times of gradual solar energetic particle (SEP) events as functions of solar source longitude: (1) T(sub 0), the time from associated CME launch to SEP onset at 1 AU, (2) T(sub R), the rise time from SEP onset to the time when the SEP intensity is a factor of 2 below peak intensity, and (3) T(sub D), the duration over which the SEP intensity is within a factor of 2 of the peak intensity. Those SEP event times are compared with associated CME speeds, accelerations, and widths to determine whether and how the SEP event times may depend on the formation and dynamics of coronal/interplanetary shocks driven by the CMEs. Solar source longitudinal variations are clearly present in the SEP times, but T(sub R)and T(sub D) are significantly correlated with CME speeds only for SEP events in the best-connected longitude range. No significant correlations between the SEP times and CME accelerations are found except for T(sub D) in one longitude range, but there is a weak correlation of T(sub R) and T(sub D) with CME widths. We also find no correlation of any SEP times with the solar wind O(exp +6)/O(exp +7) values, suggesting no dependence on solar wind stream type. The SEP times of the small subset of events occurring in interplanetary CMEs may be slightly shorter than those of all events.
Download or read book Corotating Interaction Regions written by A. Balogh and published by Springer Science & Business Media. This book was released on 2000-01-31 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume gives a comprehensive and integrated overview of current knowledge and understanding of corotating interaction regions (CIRs) in the solar wind. It is the result of a workshop at ISSI, where space scientists involved in the Ulysses, Pioneer, Voyager, IMP-8, Wind, and SOHO missions exchanged their data and interpretations with theorists in the fields of solar and heliospheric physics. The book provides a broad synthesis of current understanding of CIRs, which form at the interface between the fast solar wind originating in the northern and southern coronal holes and the slow solar wind that originates near and within coronal streamers surrounding the heliomagnetic equator. CIRs are the dominant structure in the heliosphere near and beyond Earth on the declining phase and near the minimum of the 11-year solar activity cycle. Particles energized at the shocks that bound CIRs at heliospheric distances beyond the orbit of Earth are the dominant energetic particle population observed in the outer heliosphere at these times. Papers included in this volume cover the subject of CIRs from their dissipation in the outer hemisphere, and include discussions of complexities associated with their evolution with distance from the Sun, their three-dimensional structure, and the myriad effects that CIRs have on energetic particles throughout the heliosphere. The book is intended to provide scientists active in space physics research with an up-to-date status report on current understanding of CIRs and their effects in the heliosphere, and also to serve the advanced graduate student with introductory material on this active field of research.
Download or read book Fast Coronal Mass Ejection Environments and the Production of Solar Energetic Particle Events written by and published by . This book was released on 2005 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The search continues for coronal environmental factors that determine whether a fast coronal mass ejection (CME) results in a solar energetic particle (SEP) event at I AU. From a plot of peak 20 MeV SEP intensities versus associated CME speeds we select for comparison two groups of fast, wide, western hemisphere CMEs observed with the LASCO coronograph from 1998 to 2002. The SEP-rich CME group produced the largest observed SEP events, and the SEP-poor CME group produced the smallest or no observed SEP events. The major differences are that the SEP-rich CMEs are brighter and more likely to be streamer blowouts and to follow colocated CMEs within 12 or 24 hours. The SEP-poor CMEs are fainter and less likely to interact with streamers or to follow preceding colocated CMEs. Thus we confirm the recent result that the SEP event peak intensities are higher when the associated driver CMEs are preceded within a day by wide CMEs at the same locations. However, the enhanced brightness, and therefore mass, of the SEP-rich CMEs appears to be their most dominant characteristic and suggests that either large longitudinal and latitudinal extents or higher densities are needed for fast CMEs to produce SEPs.
Download or read book Solar Cosmic Rays written by L.I. Miroshnichenko and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Solar Eruptions and Energetic Particles written by N. Gopalswamy and published by American Geophysical Union. This book was released on 2006-01-10 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 165. Coronal mass ejections (CMEs) are the most energetic events in the heliosphere. During solar cycle 23, the close connection between CMEs and solar energetic particles (SEPs) was studied in much greater detail than was previously possible, including effects on space weather. This book reviews extensive observations of solar eruptions and SEPs from orbiting and ground-based systems. From SOHO and ACE to RHESSI and TRACE, we now have measurements of unprecedented sensitivity by which to test assumptions and refine models. Discussion and analysis of: Coronal mass ejections and energetic particles over one solar cycle Implications of solar eruptions for space weather and human space exploration The elemental, isotopic, and ionic charge state composition of accelerated particles Complex interconnections among CMEs, flares, shocks, and energetic particles will make this book an indispensable resource for scientists working on the Sun-Earth connection, including space physicists, magnetospheric physicists, atmospheric physicists, astrophysicists, and aeronomists.
Download or read book Interplanetary Magnetohydrodynamics written by L. F. Burlaga and published by Oxford University Press, USA. This book was released on 1995-09-07 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data from spacecraft such as Pioneer, Vela and Voyager have revealed the interstellar medium to be a remarkable physical system, which has served as a laboratory for the study of turbulent, supersonic, ideal magnetohydrodynamic (MHD) flows. The results of these studies provided confirmation of many theoretical models of the interstellar medium.
Download or read book Cosmic Rays at Earth written by P.K.F. Grieder and published by Elsevier. This book was released on 2001-07-27 with total page 1117 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1912 Victor Franz Hess made the revolutionary discovery that ionizing radiation is incident upon the Earth from outer space. He showed with ground-based and balloon-borne detectors that the intensity of the radiation did not change significantly between day and night. Consequently, the sun could not be regarded as the sources of this radiation and the question of its origin remained unanswered. Today, almost one hundred years later the question of the origin of the cosmic radiation still remains a mystery.Hess' discovery has given an enormous impetus to large areas of science, in particular to physics, and has played a major role in the formation of our current understanding of universal evolution. For example, the development of new fields of research such as elementary particle physics, modern astrophysics and cosmology are direct consequences of this discovery. Over the years the field of cosmic ray research has evolved in various directions: Firstly, the field of particle physics that was initiated by the discovery of many so-called elementary particles in the cosmic radiation. There is a strong trend from the accelerator physics community to reenter the field of cosmic ray physics, now under the name of astroparticle physics. Secondly, an important branch of cosmic ray physics that has rapidly evolved in conjunction with space exploration concerns the low energy portion of the cosmic ray spectrum. Thirdly, the branch of research that is concerned with the origin, acceleration and propagation of the cosmic radiation represents a great challenge for astrophysics, astronomy and cosmology. Presently very popular fields of research have rapidly evolved, such as high-energy gamma ray and neutrino astronomy. In addition, high-energy neutrino astronomy may soon initiate as a likely spin-off neutrino tomography of the Earth and thus open a unique new branch of geophysical research of the interior of the Earth. Finally, of considerable interest are the biological and medical aspects of the cosmic radiation because of it ionizing character and the inevitable irradiation to which we are exposed. This book is a reference manual for researchers and students of cosmic ray physics and associated fields and phenomena. It is not intended to be a tutorial. However, the book contains an adequate amount of background materials that its content should be useful to a broad community of scientists and professionals. The present book contains chiefly a data collection in compact form that covers the cosmic radiation in the vicinity of the Earth, in the Earth's atmosphere, at sea level and underground. Included are predominantly experimental but also theoretical data. In addition the book contains related data, definitions and important relations. The aim of this book is to offer the reader in a single volume a readily available comprehensive set of data that will save him the need of frequent time consuming literature searches.
Download or read book Solar Particle Radiation Storms Forecasting and Analysis written by Olga E Malandraki and published by . This book was released on 2020-10-08 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Solar Particle Radiation Storms Forecasting and Analysis written by Olga E. Malandraki and published by Springer. This book was released on 2018-02-01 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 book is published with open access under a CC BY license.
Download or read book Coronal Mass Ejections written by H. Kunow and published by Springer Science & Business Media. This book was released on 2007-12-03 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book is intended to provide scientists active in space physics research with an up-to-date status of the current understanding of CMEs and ICMEs and their effects in the heliosphere. It also serves the advanced graduate student with introductory material on this active field of research. New sets of open questions are presented for further studies as well as for new instruments and missions under development.
Download or read book Tracking the Evolution of Successful Coronal Mass Ejections CMEs written by Wafaa Zaki and published by . This book was released on 2016-07-21 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Coronal and Stellar Mass Ejections IAU S226 written by International Astronomical Union. Symposium and published by Cambridge University Press. This book was released on 2005-07-04 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the IAU Symposium on Coronal and Stellar Mass Ejections.
Download or read book Solar Terrestrial Magnetic Activity and Space Environment written by H. Wang and published by Elsevier. This book was released on 2002-11-20 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: The COSPAR Colloquium on Solar-Terrestrial Magnetic Activity and Space Environment (STMASE) was held in the National Astronomy Observatories of Chinese Academy of Sciences (NAOC) in Beijing, China in September 10-12, 2001. The meeting was focused on five areas of the solar-terrestrial magnetic activity and space environment studies, including study on solar surface magnetism; solar magnetic activity, dynamical response of the heliosphere; space weather prediction; and space environment exploration and monitoring. A hot topic of space research, CMEs, which are widely believed to be the most important phenomenon of the space environment, is discussed in many papers. Other papers show results of observational and theoretical studies toward better understanding of the complicated image of the magnetic coupling between the Sun and the Earth, although little is still known little its physical background. Space weather prediction, which is very important for a modern society expanding into out-space, is another hot topic of space research. However, a long way is still to go to predict exactly when and where a disaster will happen in the space. In that sense, there is much to do for space environment exploration and monitoring. The manuscripts submitted to this Monograph are divided into the following parts: (1) solar surface magnetism, (2) solar magnetic activity, (3) dynamical response of the heliosphere, (4) space environment exploration and monitoring; and (5) space weather prediction. Papers presented in this meeting but not submitted to this Monograph are listed by title as unpublished papers at the end of this book.
