A Statistical Study of EMIC Waves Observed by Cluster. 1. Wave Properties. EMIC Wave Properties PDF Download

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Category :
Languages : en
Pages : 19

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Electromagnetic ion cyclotron (EMIC) waves are an important mechanism for particle energization and losses inside the magnetosphere. In order to better understand the effects of these waves on particle dynamics, detailed information about the occurrence rate, wave power, ellipticity, normal angle, energy propagation angle distributions, and local plasma parameters are required. Previous statistical studies have used in situ observations to investigate the distribution of these parameters in the magnetic local time versus L-shell (MLT-L) frame within a limited magnetic latitude (MLAT) range. In our study, we present a statistical analysis of EMIC wave properties using 10 years (2001-2010) of data from Cluster, totaling 25,431 min of wave activity. Due to the polar orbit of Cluster, we are able to investigate EMIC waves at all MLATs and MLTs. This allows us to further investigate the MLAT dependence of various wave properties inside different MLT sectors and further explore the effects of Shabansky orbits on EMIC wave generation and propagation. Thus, the statistical analysis is presented in two papers. OUr paper focuses on the wave occurrence distribution as well as the distribution of wave properties. The companion paper focuses on local plasma parameters during wave observations as well as wave generation proxies.

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Languages : en
Pages : 16

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We perform a statistical study of electromagnetic ion cyclotron (EMIC) waves detected by the Van Allen Probes mission to investigate the spatial distribution of their occurrence, wave power, ellipticity, and normal angle. The Van Allen Probes have been used which allow us to explore the inner magnetosphere (1.1 to 5.8 RE). Magnetic field measurements from the Electric and Magnetic Field Instrument Suite and Integrated Science on board the Van Allen Probes are used to identify EMIC wave events for the first 22 months of the mission operation (8 September 2012 to 30 June 2014). EMIC waves are examined in H-, He+-, and O+-bands. Over 700 EMIC wave events have been identified over the three different wave bands (265 H+-band events, 438 He+-band events, and 68 O+-band events). EMIC wave events are observed between L = 2 - 8, with over 140 EMIC wave events observed below L = 4. The results show that H+-band EMIC waves have two peak magnetic local time (MLT) occurrence regions: pre-noon (09:00 MLT d"12:00) and afternoon (15:00

Author: Nicola Fox
Publisher: Springer
ISBN: 9781489978707
Category : Science
Languages : en
Pages : 0

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Documents the science, the mission, the spacecraft and the instrumentation on a unique NASA mission to study the Earth’s dynamic, dangerous and fascinating Van Allen radiation belts that surround the planet This collection of articles provides broad and detailed information about NASA’s Van Allen Probes (formerly known as the Radiation Belt Storm Probes) twin-spacecraft Earth-orbiting mission. The mission has the objective of achieving predictive understanding of the dynamic, intense, energetic, dangerous, and presently unpredictable belts of energetic particles that are magnetically trapped in Earth’s space environment above the atmosphere. It documents the science of the radiation belts and the societal benefits of achieving predictive understanding. Detailed information is provided about the Van Allen Probes mission design, the spacecraft, the science investigations, and the onboard instrumentation that must all work together to make unprecedented measurements within a most unforgiving environment, the core of Earth’s most intense radiation regions. This volume is aimed at graduate students and researchers active in space science, solar-terrestrial interactions and studies of the upper atmosphere. Originally published in Space Science Reviews, Vol. 179/1-4, 2013.

Author: Andreas Keiling
Publisher: John Wiley & Sons
ISBN: 1119054958
Category : Science
Languages : en
Pages : 524

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Low-frequency waves in space plasmas have been studied for several decades, and our knowledge gain has been incremental with several paradigm-changing leaps forward. In our solar system, such waves occur in the ionospheres and magnetospheres of planets, and around our Moon. They occur in the solar wind, and more recently, they have been confirmed in the Sun’s atmosphere as well. The goal of wave research is to understand their generation, their propagation, and their interaction with the surrounding plasma. Low-frequency Waves in Space Plasmas presents a concise and authoritative up-to-date look on where wave research stands: What have we learned in the last decade? What are unanswered questions? While in the past waves in different astrophysical plasmas have been largely treated in separate books, the unique feature of this monograph is that it covers waves in many plasma regions, including: Waves in geospace, including ionosphere and magnetosphere Waves in planetary magnetospheres Waves at the Moon Waves in the solar wind Waves in the solar atmosphere Because of the breadth of topics covered, this volume should appeal to a broad community of space scientists and students, and it should also be of interest to astronomers/astrophysicists who are studying space plasmas beyond our Solar System.

Author: J. A. Jacobs
Publisher: Springer Science & Business Media
ISBN: 3642868282
Category : Science
Languages : en
Pages : 187

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Book Description
The subject of geomagnetic micropulsations has developed extremely rapidly and it is difficult to know when is an appropriate time to pause and assess the sum total of our knowledge-both observational and theoretical. There has in recent years been a tremendous increase in both the quantity and quality of data and also many theoretical ad vances in our understanding of the phenomenon. Undoubtedly there will be further progress in both areas but it seems worthwhile now to review both our knowledge and our ignorance. This book was essen tially completed by the end of April 1969 and tries to give a summary of the subject up to that time. The Earth is enclosed in the magnetosphere, a hollow carved out of the solar wind by the Earth's magnetic field. Above the ionosphere there is a very tenuous thermal plasma of partially ionized hydrogen in diffusive equilibrium with magnetic and gravitational forces, and ener getic protons and electrons that constitute the trapped Van Allen ra diation belts. Throughout this anisotropic and inhomogeneous plasma, natural and man-made electromagnetic energy propagates in a wide variety of modes and frequency bands. This book is concerned with that class of natural signals called geomagnetic micropulsations-short period (usually of the order of seconds or minutes) fluctuations of the Earth's magnetic field.

Author: Kenneth Davies
Publisher: IET
ISBN: 9780863411861
Category : Science
Languages : en
Pages : 612

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Book Description
This introductory text replaces two earlier publications (Davies 1965, 1969). Among the topics: characteristics of waves and plasma, the solar-terrestrial system, the Appleton formula, radio soundings of the ionosphere, morphology of the ionosphere, oblique propagation, importance of amplitude and phase, earth-space propagation. Annotation copyrighted by Book News, Inc., Portland, OR

Author: Johnny Saldana
Publisher: SAGE
ISBN: 1446200124
Category : Reference
Languages : en
Pages : 282

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Book Description
The Coding Manual for Qualitative Researchers is unique in providing, in one volume, an in-depth guide to each of the multiple approaches available for coding qualitative data. In total, 29 different approaches to coding are covered, ranging in complexity from beginner to advanced level and covering the full range of types of qualitative data from interview transcripts to field notes. For each approach profiled, Johnny Saldaña discusses the method’s origins in the professional literature, a description of the method, recommendations for practical applications, and a clearly illustrated example.

Author: James L. Burch
Publisher: Springer Science & Business Media
ISBN: 0387898204
Category : Science
Languages : en
Pages : 575

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Book Description
J.L. Burch·V. Angelopoulos Originally published in the journal Space Science Reviews, Volume 141, Nos 1–4, 1–3. DOI: 10.1007/s11214-008-9474-5 © Springer Science+Business Media B.V. 2008 The Earth, like all the other planets, is continuously bombarded by the solar wind, which is variable on many time scales owing to its connection to the activity of the Sun. But the Earth is unique among planets because its atmosphere, magnetic eld, and rotation rates are each signi cant, though not dominant, players in the formation of its magnetosphere and its reaction to solar-wind inputs. An intriguing fact is that no matter what the time scale of solar-wind variations, the Earth’s response has a de nite pattern lasting a few hours. Known as a magnetospheric substorm, the response involves a build-up, a crash, and a recovery. The build-up (known as the growth phase) occurs because of an interlinking of the geom- netic eld and the solar-wind magnetic eld known as magnetic reconnection, which leads to storage of increasing amounts of magnetic energy and stress in the tail of the mag- tosphere and lasts about a half hour. The crash (known as the expansion phase) occurs when the increased magnetic energy and stresses are impulsively relieved, the current system that supports the stretched out magnetic tail is diverted into the ionosphere, and bright, dynamic displays of the aurora appear in the upper atmosphere. The expansion and subsequent rec- ery phases result from a second magnetic reconnection event that decouples the solar-wind and geomagnetic elds.

Author: Joseph E. Borovsky
Publisher: Frontiers Media SA
ISBN: 2832522491
Category : Science
Languages : en
Pages : 223

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Book Description
Cold-ion populations and cold-electron populations are extremely difficult to measure in the Earth’s magnetosphere, and their properties, evolutions, and controlling factors are poorly understood. They are sometimes referred to as the “hidden populations”. But they are known to have multiple impacts on the behavior of the global magnetospheric system. These impacts include (a) the reduction of the dayside reconnection rate and consequently the reduction of solar-wind/magnetosphere coupling, (b) alteration of the growth rate and saturation amplitudes of plasma waves resulting in alterations of the energization rates of the radiation belts, (c) changes in plasma-wave properties resulting in changes in the loss rates of the ring current and radiation belts, (d) changes in the mass density of the magnetosphere resulting in changes in the radial diffusion of the radiation belts, (e) spatial and temporal structuring of the aurora, (f) altering magnetotail reconnection, (g) changing spacecraft charging, and (h) acting as sources for warm and hot magnetospheric populations. A recent workshop on the cold-particle populations of the magnetosphere inspired new work on the outstanding problems caused by a lack of understanding of those cold populations. This Research Topic will collect reports of that new work and will stimulate the formation of author teams to write review articles on what is known and what needs to be known. Commentaries assessing the present situation and guiding the research field into the future will be solicited from the community. Methods articles describing new measurement techniques and new spaceflight mission concepts will be welcomed.

Author: Yukitoshi Nishimura
Publisher: Elsevier
ISBN: 0128213736
Category : Science
Languages : en
Pages : 566

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Cross-Scale Coupling and Energy Transfer in the Magnetosphere-Ionosphere-Thermosphere System provides a systematic understanding of Magnetosphere-Ionosphere-Thermosphere dynamics. Cross-scale coupling has become increasingly important in the Space Physics community. Although large-scale processes can specify the averaged state of the system reasonably well, they cannot accurately describe localized and rapidly varying structures in space in actual events. Such localized and variable structures can be as intense as the large-scale features. This book covers observations on quantifying coupling and energetics and simulation on evaluating impacts of cross-scale processes. It includes an in-depth review and summary of the current status of multi-scale coupling processes, fundamental physics, and concise illustrations and plots that are usable in tutorial presentations and classrooms. Organized by physical quantities in the system, Cross-Scale Coupling and Energy Transfer in the Magnetosphere-Ionosphere-Thermosphere System reviews recent advances in cross-scale coupling and energy transfer processes, making it an important resource for space physicists and researchers working on the magnetosphere, ionosphere, and thermosphere. Describes frontier science and major science around M-I-T coupling, allowing for foundational understanding of this emerging field in space physics Reviews recent and key findings in the cutting-edge of the science Discusses open questions and pathways for understanding how the field is evolving