Download or read book The Evolution and Motion of Transient Events in the Solar Wind magnetosphere Interaction written by Yaireska Marie Collado-Vega and published by . This book was released on 2013 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Instabilities in the solar wind-magnetosphere interaction govern the entry of solar wind particles into the Earth's magnetosphere. These particles could ultimately be responsible for serious damage to our current technological systems. I use simulations and observations to investigate two kinds of instabilities that occur during unsteady interaction, magnetopause vortices and bursty reconnection resulting in flux transfer events (FTEs). For the magnetopause vortices analysis, magnetohydrodynamic (MHD) simulations were generated. Two cases were run, one for a nominal speed solar wind (360 km/s) and another for a high speed solar wind (700 km/s). Both cases had an abrupt change in the interplanetary magnetic field (IMF) orientation; 15 minutes being southward, -5 nT, and then turning northward, +5 nT, for two hours. No other parameter was changed in these runs. Using an IDL-based tool, I visualized the 2D and 3D nature of the vortices and compared my results with those obtained previously by Collado-Vega et al. (2007) who studied vortices using simulated MHD data initiated by real solar wind conditions. The characteristics of the vortices formed under dynamic solar wind conditions are consistent with vortices driven by surface waves on the magnetopause, like the Kelvin-Helmholtz (KH) instability. However, the majority of those developed under steady solar wind conditions suggest otherwise, especially the ones that developed on the dayside which are believed to be formed by the convection pattern created by high latitude reconnection. For the study of FTEs, I focus on Cluster satellite magnetopause encounters. The Cluster satellites orbit in a tetrahedral formation in near-polar orbits. I identified FTEs in Cluster observations from 2002 to 2003, and a total of 109 events were counted in the data set. A comparison of the analytical and global MHD simulation results indicates that most of the events form by component reconnection along a tilted subsolar reconnection line, move antisunward with the magnetosheath flow, and have long spatial extent. The events that were observed to have a motion opposite to the magnetosheath motion were found to have a strong By IMF component that can contribute to the flow reversal process.

Download or read book Dayside Magnetosphere Interactions written by Qiugang Zong and published by John Wiley & Sons. This book was released on 2020-03-13 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Exploring the processes and phenomena of Earth’s dayside magnetosphere Energy and momentum transfer, initially taking place at the dayside magnetopause, is responsible for a variety of phenomenon that we can measure on the ground. Data obtained from observations of Earth’s dayside magnetosphere increases our knowledge of the processes by which solar wind mass, momentum, and energy enter the magnetosphere. Dayside Magnetosphere Interactions outlines the physics and processes of dayside magnetospheric phenomena, the role of solar wind in generating ultra-low frequency waves, and solar wind-magnetosphere-ionosphere coupling. Volume highlights include: Phenomena across different temporal and spatial scales Discussions on dayside aurora, plume dynamics, and related dayside reconnection Results from spacecraft observations, ground-based observations, and simulations Discoveries from the Magnetospheric Multiscale Mission and Van Allen Probes era Exploration of foreshock, bow shock, magnetosheath, magnetopause, and cusps Examination of similar processes occurring around other planets 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.

Download or read book Solar wind Magnetosphere interaction written by Simon Wing and published by Frontiers Media SA. This book was released on 2023-07-05 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dayside Aurora and Its Connection to the Solar Wind Magnetosphere Ionosphere Interaction written by Boyi Wang and published by . This book was released on 2018 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents a comprehensive study of the dayside auroral dynamics and remote sensing of coupled magnetosphere-ionosphere system responses to various upstream disturbances, which include interplanetary magnetic field (IMF) discontinuities, foreshock transients, and magnetosheath high speed jets (HSJs). Recent studies have shown that these disturbances have significant impacts on coupled magnetosphere-ionosphere system, changing the particle transportation and energy budget. However, it has been difficult to find spatial structure and evolution of the interaction processes using a limited number of in-situ measurements. This dissertation aims to understand how dayside aurora and airglow respond to upstream disturbances, and to utilize auroral imaging to determine how the magnetosphere-ionosphere system responds to the upstream disturbances. Our study takes a unique approach by taking advantage of high-resolution 2D imaging to vastly increase community's understanding of magnetosphere-ionosphere responses to upstream disturbances, through tracing location, size and propagation of optical structures. We first examine the role of IMF southward turnings as the trigger of Poleward Moving Auroral Forms (PMAFs), which are thought to be an ionospheric signature of dayside magnetic reconnection. While PMAFs are more likely to occur when the IMF is southward, how often PMAFs are triggered by changes in solar wind parameters is still a major open question and has only been poorly understood due to the use of solar wind monitors far away from the bow shock. This dissertation addresses this question with the conjunction between the all-sky imager (ASI) at Automatic Geophysical Observatories (AGO) P1 station in Antarctica and the Time History of Events and Macroscale Interactions during Substorms (THEMIS) B and C satellites, which provide much more accurate solar wind conditions than the solar wind monitors at the L1 point. In a statistical study using 60 PMAF events, 70% of the events show a reduction of IMF Bz before PMAF onset, which indicates that IMF southward turning plays an important role in triggering a majority of PMAFs. Those PMAFs were further found to evolve to polar cap airglow patches. This dissertation investigates how often polar cap patches originate in PMAFs and are associated with flow channels, using the conjunction between the ASI at the AGO P1 station and DMSP satellites. Our 50-event statistical study shows that in a majority (45) of events, longitudinally narrow flow enhancements directed anti-sunward are found to be collocated with the patches, have velocities (up to a few km/s) substantially larger than the large-scale background flows (~500 m/s) and have widths comparable to patch widths (~400 km). The patches emanated out of PMAFs and were found to have a large IMF By dependence on the MLT of patches entering the polar cap. Through investigation of dayside aurora, we noticed that auroral brightenings can occur even without substantial changes in the IMF Bz or dynamic pressure. We examined whether disturbances generated in the foreshock and magnetosheath can contribute to dayside auroral brightening. Studies of the impact of foreshock and magnetosheath transients on the magnetosphere-ionosphere system are very limited, and it has been difficult to find how the transients interact in individual events due to limited in-situ and space-based imaging observations. In this dissertation, the conjunction between the ASI at South Pole and the THEMIS satellites during 2008 through 2011 is utilized to determine the magnetosphere-ionosphere responses to foreshock transients and magnetosheath HSJs in a 2D perspective. In situ observation by the THEMIS satellites showed that a foreshock transient during 1535-1545 UT on 25 June 2008 was associated with magnetospheric compression. The ASI at South Pole observed that both diffuse and discrete aurora brightened locally soon after the appearance of this foreshock transient. With the advantage of the high-resolution 2D imaging, we were able to determine that the diffuse auroral brightening corresponds to a localized azimuthal extent of a few Re size on the equatorial plane, and propagated duskward with an average speed of ~100 km/s. Similarly, we for the first time show a nearly one-to-one relationship between the HSJs and individual localized discrete/diffuse auroral brightenings using eight HSJ events. The azimuthal size of HSJ-related diffuse auroral signatures is ~800 km at 230-km altitude in the ionosphere and ~3.7 Re in the magnetosphere, which is slightly larger but of the order of the cross-sectional diameter of HSJs (~1 Re). Furthermore, most of those auroral signatures have azimuthal motions, whose magnitude and direction agree with magnetosheath background flows. In addition to magnetospheric compression, foreshock transients were also found to cause Pc5-band (150-600s) ultra-low frequency (ULF) waves, which are important in transporting mass, energy and momentum in the coupled magnetosphere-ionosphere system. Although it is difficult to find spatial structure of dayside Pc5 waves by a small number of satellites or ground magnetometers, we have successfully determined the 2D structure and motion of ULF waves in the ionosphere using optical imagers. This dissertation reports two series of foreshock-driven Pc5 waves, which are found to be field line resonances (FLRs). The ground-based ASI at South Pole shows that periodic poleward moving east-west arcs are the ionospheric signature of FLRs. The azimuthal distribution, including dawn-dusk symmetricity and azimuthal wavenumbers, of the FLRs in the magnetosphere, are further determined by 2D imaging. The fine structure embedded in the large-scale arcs indicates a wave with high toroidal wavenumber (m ~ 140) was coupled with the FLRs. Based on these works, a likely scenario revealed from the satellite-imaging coordinated observations is as follows: Foreshock transients and magnetosheath HSJs drive compressions of the magnetopause at a few RE, much more localized than global compression by shocks. The compressions launch fast-mode waves and FLRs, which create localized electron precipitation and auroral brightenings. The auroral responses found in this study can highlight structure and evolution of the magnetospheric and ionospheric responses, and signify the geoeffectiveness of localized and transient upstream energy input.

Download or read book The Atmosphere and Climate of Mars written by Robert M. Haberle and published by Cambridge University Press. This book was released on 2017-06-29 with total page 613 pages. Available in PDF, EPUB and Kindle. Book excerpt: Humanity has long been fascinated by the planet Mars. Was its climate ever conducive to life? What is the atmosphere like today and why did it change so dramatically over time? Eleven spacecraft have successfully flown to Mars since the Viking mission of the 1970s and early 1980s. These orbiters, landers and rovers have generated vast amounts of data that now span a Martian decade (roughly eighteen years). This new volume brings together the many new ideas about the atmosphere and climate system that have emerged, including the complex interplay of the volatile and dust cycles, the atmosphere-surface interactions that connect them over time, and the diversity of the planet's environment and its complex history. Including tutorials and explanations of complicated ideas, students, researchers and non-specialists alike are able to use this resource to gain a thorough and up-to-date understanding of this most Earth-like of planetary neighbours.

Download or read book Earth affecting Solar Transients written by Jie Zhang and published by Springer. This book was released on 2018-10-27 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth-affecting solar transients encompass a broad range of phenomena, including major solar flares, CMEs, ICMEs, solar energetic particle events, and corotating interaction regions.​ In the past decade, nearly continuous observations of the Sun and the inner heliosphere with an unprecedented wide spatial coverage from a fleet of spacecraft, including STEREO Ahead/Behind, SDO, SOHO, Messenger, Venus Express, ACE and WIND, in combination with a significant advancement of global MHD numerical simulation and theoretical analysis, have greatly improved our understanding of solar transients and the prediction of their potential impact on Earth. This Topical Collection is based on the International Study of Earth-affecting Solar Transients (ISEST) project, initially launched in 2013 to bring together scientists from many countries to join efforts on studying solar transients. ISEST became one of the four research projects of the Variability of the Sun and Its Terrestrial Impact (VarSITI) program, sponsored by the Scientific Committee on Solar-Terrestrial Physics (SCOSTEP) for the period of 2014 – 2018. Originally published in the journal Solar Physics, volumes 292 (2017) and 293 (2018).

Download or read book Analysing the Motion of Solar Wind Transients Using Stereo hi Observations written by Anthony Owen Williams and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Dynamic Magnetosphere written by William Liu and published by Springer Science & Business Media. This book was released on 2011-06-21 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the plethora of monographs published in recent years, few cover recent progress in magnetospheric physics in broad areas of research. While a topical focus is important to in-depth views at a problem, a broad overview of our field is also needed. The volume answers to the latter need. With the collection of articles written by leading scientists, the contributions contained in the book describe latest research results in solar wind-magnetosphere interaction, magnetospheric substorms, magnetosphere-ionosphere coupling, transport phenomena in the plasma sheet, wave and particle dynamics in the ring current and radiation belts, and extra-terrestrial magnetospheric systems. In addition to its breadth and timeliness, the book highlights innovative methods and techniques to study the geospace.

Download or read book Analysing the Motion of Solar Wind Transients Using Stereo written by Anthony Owen Williams and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examines a technique used to study solar wind transients with the STEREO heliospheric imagers. We perform a manual extraction of profiles of transient events from elongation-time plots and apply this technique to the profiles. The technique assumes we are studying a point like object travelling at a constant speed and extracts the speed of the object and the direction it is travelling relative to the observer. We first examine the errors involved in performing the manual extraction of the profiles and from this conclude that any errors introduced are small and can easily be taken into account. Having examined the errors we then apply the technique to the two types of transient events, corotating interaction regions and coronal mass ejections. Corotating interaction regions have a spiral form and as such this technique should not work in determining their speed and position. However observations show that corotating interaction regions are made up of smaller scale transients which can be tracked. We were able to use this technique combined with in-situ measurements to track corotating interaction regions throughout the inner solar system. Coronal mass ejections are generally larger one-off events which can be more easily analysed by this technique. We examine several coronal mass ejections with the technique and confirm the measurements of speed and direction with in-situ measurements at Earth. We then discuss the assumptions involved in the technique and how they might affect the STEREO observations. We conclude that this technique can be used to track all types of solar wind transients and that future work should focus on further assessment of the assumptions.

Download or read book Earth affecting Solar Transients written by Jie Zhang and published by Springer. This book was released on 2018-12-29 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earth-affecting solar transients encompass a broad range of phenomena, including major solar flares, CMEs, ICMEs, solar energetic particle events, and corotating interaction regions.​ In the past decade, nearly continuous observations of the Sun and the inner heliosphere with an unprecedented wide spatial coverage from a fleet of spacecraft, including STEREO Ahead/Behind, SDO, SOHO, Messenger, Venus Express, ACE and WIND, in combination with a significant advancement of global MHD numerical simulation and theoretical analysis, have greatly improved our understanding of solar transients and the prediction of their potential impact on Earth. This Topical Collection is based on the International Study of Earth-affecting Solar Transients (ISEST) project, initially launched in 2013 to bring together scientists from many countries to join efforts on studying solar transients. ISEST became one of the four research projects of the Variability of the Sun and Its Terrestrial Impact (VarSITI) program, sponsored by the Scientific Committee on Solar-Terrestrial Physics (SCOSTEP) for the period of 2014 – 2018. Originally published in the journal Solar Physics, volumes 292 (2017) and 293 (2018).

Download or read book Space Weather Fundamentals written by George V. Khazanov and published by CRC Press. This book was released on 2016-11-17 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Space weather is one of the most significant natural hazards to human life and health. Conditions of the sun and in the solar wind, magnetosphere, ionosphere, and thermosphere can influence the performance and reliability of space-borne and ground-based technological systems. If conditions in the space environment are adverse, they can cause disruption of satellite operations, communications, navigation, and electric power distribution grids, leading to a variety of socioeconomic losses. This book provides an overview of our current knowledge and theoretical understanding of space weather formation and covers all major topics of this phenomena, from the sun to the Earth’s ionosphere and thermosphere, thus providing a fully updated review of this rapidly advancing field. The book brings together an outstanding team of internationally recognised contributors to cover topics such as solar wind, the earth's magnetic field, radiation belts, the aurora, spacecraft charging, orbital drag and GPS.

Download or read book Solar Wind Earth s Magnetosphere Interaction Halloween Event Modelling written by Suleiman Barkara and published by . This book was released on 2016-08-21 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Solar Magnetic Fields written by Brandon Burkholder and published by . This book was released on 2019 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetized plasmas with twisted and filamented magnetic fields are pervasive throughout the heliosphere. In the solar magnetic field, photospheric convection on scale sizes from granules to differential rotation is responsible for driven magnetic reconnection. These reconnection sites are closely related to the magnetic topology, which is highly complex as the magnetic field is structured by a network of many thousands of magnetic flux concentrations. The coronal plasma overlying this "magnetic carpet" is the source of the solar wind flow, which has been found to be turbulent as close to the sun as our observations can currently resolve. At 1 AU, observations have also revealed a highly structured solar wind which we posit in this thesis originates in the corona rather than forming in-transit. Further, the solar wind-magnetosphere interaction depends on variability in the solar wind. When the boundary between solar wind plasma and magnetospheric plasma is unstable to the growth of Kelvin-Helmholtz waves, driven magnetic reconnection can occur on the magnetopause boundary. Such reconnection allows magnetic field to thread the boundary and transport can take place. We quantify the solar wind interaction for a corotation dominated system in terms of the mass and momentum transport driven by Kelvin-Helmholtz instabilities. Model-data comparisons are performed in this thesis using both the magnetohydrodynamic and hybrid-kinetic approaches for fluid simulations.

Download or read book Space Physics and Aeronomy Magnetospheres in the Solar System written by Romain Maggiolo and published by John Wiley & Sons. This book was released on 2021-04-14 with total page 800 pages. Available in PDF, EPUB and Kindle. Book excerpt: Überblick über den aktuellen Wissensstand und künftige Forschungsrichtungen in der Magnetosphärenphysik In den sechs Jahrzehnten seit der Einführung des Begriffs ?Magnetosphäre? sind über den magnetisierten Raum, der jeden Körper in unserem Sonnensystem umgibt, viele Theorien entstanden und viele Erkenntnisse gewonnen worden. Jede Magnetosphäre ist einzigartig und verhält sich doch entsprechend den universellen physikalischen Vorgängen. Der Band ?Magnetospheres in the Solar System? enthält Beiträge von Experten für Experimentalphysik, theoretische Physik und numerische Modellierung, die einen Überblick über verschiedene Magnetosphären vermitteln, von der winzigen Magnetosphäre des Merkur bis zu den gewaltigen planetarischen Magnetosphären von Jupiter und Saturn. Das Werk bietet insbesondere: * Einen kompakten Überblick über die Geschichte der Magnetosphäre, ihre Grundsätze und Gleichungen * Eine Zusammenfassung der grundlegenden Prozesse in der Magnetospährenphysik * Instrumente und Techniken zur Untersuchung von Prozessen in der Magnetosphäre * Eine besondere Schwerpunktsetzung auf die Magnetosphäre der Erde und ihre Dynamik * Eine Darstellung der planetaren Magnetfelder und Magnetosphären im gesamten Sonnensystem * Eine Definition der künftigen Forschungsrichtungen in der Magnetosphärenphysik Die Amerikanische Geophysikalische Vereinigung fördert die wissenschaftliche Erforschung der Erde und des Weltraums zum Wohle der Menschheit. In ihren Publikationen werden wissenschaftliche Erkenntnisse veröffentlicht, die Forschern, Studenten und Fachkräften zur Verfügung stehen.

Download or read book Solar and Space Physics written by National Research Council and published by National Academies Press. This book was released on 2014-09-25 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2010, NASA and the National Science Foundation asked the National Research Council to assemble a committee of experts to develop an integrated national strategy that would guide agency investments in solar and space physics for the years 2013-2022. That strategy, the result of nearly 2 years of effort by the survey committee, which worked with more than 100 scientists and engineers on eight supporting study panels, is presented in the 2013 publication, Solar and Space Physics: A Science for a Technological Society. This booklet, designed to be accessible to a broader audience of policymakers and the interested public, summarizes the content of that report.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975 with total page 1396 pages. Available in PDF, EPUB and Kindle. Book excerpt: