Download or read book Topside Ionosphere and Inner Plasmasphere at Low Solar Flux written by Sevag Derghazarian and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents several detailed observations of the upper portion of the topside ionosphere and inner plasmasphere during low solar flux conditions using Jicamarca's VHF radar. This is followed by theoretical derivations and numerical simulations that aim to present the reader with valuable information and insights into this layer of the upper atmosphere. Measurements of ionospheric parameters are first presented followed by observations of a new class of non-thermal plasma density irregularities that manifest in the equatorial topside ionosphere and inner plasmasphere above Jicamarca in the nighttime and post-midnight sectors. Measurements of ionospheric parameters such as topside density, temperature, ion composition and transition height were acquired during the recent deep solar minimum and correspond to experiments run in October, 2019, February, 2020, and September, 2020. The main features observed are a large and extended decrease in noontime temperatures unlike that seen in studies at moderate solar flux levels, predawn ionospheric heating as early as 0300 LT, large day-to-day variability in the O+/H+ transition height, and negligible helium ion concentration at all altitudes. We also analyze the data in light of the SAMI2-PE model which shows less agreement with the data than at higher solar flux. The main areas of discrepancy with the data are outlined, such as the absence of significant predawn heating, less pronounced decreases in noontime temperatures, and much higher O+ fractions at high altitudes, particularly in September. A discussion is presented on bridging the discrepancies in future model runs. Novel techniques of clutter removal and noise power bias correction are introduced and described in Appendix A. The new class of plasma density irregularities observed in the topside ionosphere and inner plasmasphere in the nighttime and post-midnight sectors are distinct from equatorial spread (ESF) in terms of their morphology and because they exhibit strong spectral sidebands at the lower-hybrid frequency. The coherent echoes were observed in a series high-altitude radar experiments performed at Jicamarca utilizing long- and coded double-pulse modes and a dual-beam mode between the years of 2018 - 2022, overlapping both the deep solar minimum of 2019 - 2020, and a subsequent period of moderately low solar flux. Observations from archival long pulse topside experiments are also presented. Doppler shifts, zonal drifts, and longitudinal dimensions of the echoes are calculated. The coded double-pulse mode was used to measure the low-frequency characteristics of the echoes with fine range resolution. The long-pulse mode was employed for high-frequency spectral analysis which revealed the presence of strong spectral sidelobes at the lower-hybrid frequency. The mechanism underlying lower hybrid waves associated with these lines is subsequently investigated. We present numerical simulations which demonstrate the feasibility of an inverse energy cascade coupled with a short wavelength instability, i.e. the lower hybrid drift instability, in explaining the waves. An inverse cascade is required for short wavelength lower hybrid waves to extend to the 3 m wavelengths measured by the Jicamarca radar. The simulations were able to reproduce multiple features of the measurements.

Download or read book Modelling the Topside Ionosphere and Plasmasphere written by COSPAR. Scientific Assembly and published by . This book was released on 2002 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Earth s Plasmasphere written by Fabien Darrouzet and published by Springer Science & Business Media. This book was released on 2009-08-21 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: James L. Burch·C. Philippe Escoubet Originally published in the journal Space Science Reviews, Volume 145, Nos 1–2, 1–2. DOI: 10. 1007/s11214-009-9532-7 © Springer Science+Business Media B. V. 2009 The IMAGE and CLUSTER spacecraft have revolutionized our understanding of the inner magnetosphere and in particular the plasmasphere. Before launch, the plasmasphere was not a prime objective of the CLUSTER mission. In fact, CLUSTER might not have ever observed this region because a few years before the CLUSTER launch (at the beginning of the 1990s), it was proposed to raise the perigee of the orbit to 8 Earth radii to make multipoint measu- ments in the current disruption region in the tail. Because of ground segment constraints, this proposal did not materialize. In view of the great depth and breadth of plasmaspheric research and numerous papers published on the plasmasphere since the CLUSTER launch, this choice certainly was a judicious one. The fact that the plasmasphere was one of the prime targets in the inner magnetosphere for IMAGE provided a unique opportunity to make great strides using the new and comp- mentary measurements of the two missions. IMAGE, with sensitive EUV cameras, could for the rst time make global images of the plasmasphere and show its great variability d- ing storm-time. CLUSTER, with four-spacecraft, could analyze in situ spatial and temporal structures at the plasmapause that are particularly important in such a dynamic system.

Download or read book Thermal Structure of the Topside Ionosphere Observed by INJUN 5 During an Intense Magnetic Storm written by W. J. Burke and published by . This book was released on 1977 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron densities and temperatures as well as omnidirectional fluxes of hyperthermal positive ions (E > 28 eV) were measured by means of spherical Langmuir probes aboard INJUN 5 at altitudes > 2000 km during a major geomagnetic storm. The electron density in the mid-latitude trough decreased and the temperatures increased during the early phases of the storm. As the storm progressed the trough's position moves equatorward with plasma depletions being observed to an invariant latitude of 40 deg during the early recovery phase. The latitude of the transition between heavy and light ion dominance also moved equatorward, but recovered at a rate slower than that of the electron trough's position. Hyperthermal ions detected in the vicinity of the trough were ring current particles reaching to the satellite's altitude. The minimum thermal electron densities in the trough were found to be within 1 deg of latitude of the maximum ring current flux. Maximum electron temperatures were measured several degrees equatorward of this position. INJUN 5 electron temperatures are compared with those measured by Alouette 2 over the reported positions of SAR arcs. The observations are also used to further evaluate a method developed for calculating the position of the ring current using ground magnetic fluctuations.

Download or read book Modeling the Ionosphere Thermosphere written by J. D. Huba and published by John Wiley & Sons. This book was released on 2014-03-17 with total page 735 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 201. Modeling the Ionosphere-Thermosphere System brings together for the first time a detailed description of the physics of the IT system in conjunction with numerical techniques to solve the complex system of equations that describe the system, as well as issues of current interest. Volume highlights include discussions of: Physics of the ionosphere and thermosphere IT system, and the numerical methods to solve the basic equations of the IT system The physics and numerical methods to determine the global electrodynamics of the IT system The response of the IT system to forcings from below (i.e., the lower atmosphere) and from above (i.e., the magnetosphere) The physics and numerical methods to model ionospheric irregularities Data assimilation techniques, comparison of model results to data, climate variability studies, and applications to space weather Providing a clear description of the physics of this system in several tutorial-like articles, Modeling the Ionosphere-Thermosphere System is of value to the upper atmosphere science community in general. Chapters describing details of the numerical methods used to solve the equations that describe the IT system make the volume useful to both active researchers in the field and students.

Download or read book Advanced Space Plasma Physics written by Wolfgang Baumjohann and published by World Scientific. This book was released on 1997-01-03 with total page 393 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book builds on the fluid and kinetic theory of equilibria and waves presented in a companion textbook, Basic Space Plasma Physics (by the same authors), but can also serve as a stand-alone text. It extends the field covered there into the domain of plasma instability and nonlinear theory.The book provides a representative selection of the many possible macro- and microinstabilities in a space plasma, from the Rayleigh-Taylor and Kelvin-Helmholtz to electrostatic and electromagnetic kinetic instabilities. Their quasilinear stabilization and nonlinear evolution and their application to space physics problems are treated. The chapters on nonlinear theory include nonlinear waves, weak turbulence and strong turbulence, all presented from the viewpoint of their relevance to space plasma physics. Special topics include auroral particle acceleration, soliton formation and caviton collapse, anomalous transport, and the theory of collisionless shocks.

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 The Earth s Ionosphere written by Michael Kelly and published by Elsevier. This book was released on 2012-12-02 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Earth's Ionosphere: Plasma Physics and Electrodynamics emphasizes the study of plasma physics and electrodynamics of the ionosphere, including many aeronomical influences. The ionosphere is somewhat of a battleground between the earth's neutral atmosphere and the sun's fully ionized atmosphere, in which the earth is embedded. One of the challenges of ionosphere research is to know enough about these two vast fields of research to make sense out of ionospheric phenomena. This book provides insights into how these competing sources of mass, momentum, and energy compete for control of the ionosphere. Some of the topics discussed include the fundamentals of ionospheric plasma dynamics; equatorial plasma instabilities; high-latitude electrodynamics; and instabilities and structure in the high-latitude ionosphere. Throughout this text only the region above 90 km are discussed, ignoring the D region entirely. This publication is a good source of information for students and individuals conducting research on earth’s ionosphere.

Download or read book The 27 Day Variations of Plasma Densities and Temperatures in the Topside Ionosphere written by and published by . This book was released on 2003 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Defense Meteorological Satellite Program (DMSP) spacecraft at 840 km observe a 27- day variation in plasma density and temperature at all subauroral latitudes. At the peak of the solar cycle, evening-sector variations are 40-50% in plasma density and 5-10% in electron temperature. The percent of variation decreases with decreasing solar activity to or below the threshold of detectability for the DMSP sensors. We compare in situ densities with simultaneous observations of total electron content but find that similar variations are not present in a consistent manner. Thus we conclude that the variations exist mostly as topside phenomena. However; comparisons with variations in the radio flux at 10.7 cm (F(sub 10.7)), a standard proxy for solar EUV, indicate that the topside variations are driven by the solar EUV flux. When compared with the variations of several alterative proxies for the solar EUV flux, we find that only one of them correlates better than F(sub 10.7). Because the topside ionosphere couples with the plasmasphere, we suggest that similar 27-day variations should appear in plasmaspheric parameters.

Download or read book The Earth s Ionosphere written by Michael C. Kelley and published by Academic Press. This book was released on 2009-06-12 with total page 593 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although interesting in its own right, due to the ever-increasing use of satellites for communication and navigation, weather in the ionosphere is of great concern. Every such system uses trans-ionospheric propagation of radio waves, waves which must traverse the commonly turbulent ionosphere. Understanding this turbulence and predicting it are one of the major goals of the National Space Weather program. Acquiring such a prediction capability will rest on understanding the very topics of this book, the plasma physics and electrodynamics of the system. Fully updated to reflect advances in the field in the 20 years since the first edition published Explores the buffeting of the ionosphere from above by the sun and from below by the lower atmosphere Unique text appropriate both as a reference and for coursework

Download or read book Plasma Sources of Solar System Magnetospheres written by Andrew F. Nagy and published by Springer. This book was released on 2016-01-27 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews what we know of the corresponding plasma source for each intrinsically magnetized planet. Plasma sources fall essentially in three categories: the solar wind, the ionosphere (both prevalent on Earth), and the satellite-related sources. Throughout the text, the case of each planet is described, including the characteristics, chemical composition and intensity of each source. The authors also describe how the plasma generated at the source regions is transported to populate the magnetosphere, and how it is later lost. To summarize, the dominant sources are found to be the solar wind and sputtered surface ions at Mercury, the solar wind and ionosphere at Earth (the relative importance of the two being discussed in a specific introductory chapter), Io at Jupiter and – a big surprise of the Cassini findings – Enceladus at Saturn. The situation for Uranus and Neptune, which were investigated by only one fly-by each, is still open and requires further studies and exploration. In the final chapter, the book offers a summary of the little we know of Uranus and Neptune, then summarizes in a comparative way what we know of plasma sources throughout the solar system, and proposes directions for future research.

Download or read book Vertical Coupling in the Atmosphere Ionosphere Magnetosphere System written by Jaroslav Chum and published by Frontiers Media SA. This book was released on 2024-01-30 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Physics of Planetary Ionospheres written by Siegfried J. Bauer and published by . This book was released on 1973 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Composition of the Low Latitude Topside Ionosphere as a Function of Longitude Season Local Time and Solar Cycle written by Keith Harold West and published by . This book was released on 1996 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book World wide Analysis and Modelling of the Ionospheric and Plasmaspheric Electron Contents by Means of Radio Occultations written by Yixie Shao and published by . This book was released on 2019 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research of this dissertation is studying the ionosphere by GPS radio occultation (RO) techniques. It is mainly divided into two parts. The first part focuses on the methodology in electron density profile retrievals from RO measurements. It aims to get more precise profiles from measured data. Classic Abel inversion is a methodology widely used in RO retrievals, and the error introduced by the spherical symmetry assumption is also well recognised. Separability Method (SM) was developed to eliminate this error in previous studies. In this work, the improvement brought by SM corresponding to classic method is checked and validated. The SM does have better performance excluding the Lack of Collocation (LoC) error. The precision of the results is also shown to depend on the accuracy of the supported GIMs, i.e., the more accurate GIMs are used, the better results can be obtained. The error in SM, introduced by the mis-modelling of using the Vertical Total Electron Content (VTEC) instead of ECLEO, the electron content below LEO height, is also checked. The result shows that it has only minor impact on the retrievals. The second part is the climatological study of topside ionosphere/bottomside plasmasphere based on the RO retrievals using SM, and aims to give a general picture of characteristics and features of these two regions in different solar periods, 2007 -- solar minimum, and 2014 – solar maximum. The empirical two-components models of topside profiles, STIP model and CPDH model, used to separate the ionospheric and plasmaspheric contribution to the VTEC measured from ground to global positioning system (GPS) satellite altitudes, are studied and validated. The conditions of applicability of the STIP model are also discussed. The same as other existing empirical models, it shows the picture of topside ionosphere till some limited altitude, which is decided by the Low Earth Orbit (LEO) satellite height used to observe the RO. The model is used to derive transition height hu and scale height hs during these two years. Generally, hu and hs show the clear diurnal, seasonal, solar cycle dependencies. The concept of IONf, the ionospheric fractional contribution to VTEC, is introduced and studied. The ionospheric features are shown and most of the ionospheric anomalies have been analyzed through this quantity. Compared to the other ionospheric related parameters, such as Ecion and Ecpl, electron content of ionosphere and plasmasphere, IONf is more stable. Hence, it is more suitable for ionosphere modelling. The Capacitor Model is used to model the consistent ‘ionospheric charging process' during the period of the day between sunrise and midday/afternoon. The model shows a good performance to reproduce real data in different circumstances and for the maximum and minimum solar activity years analyzed.

Download or read book Magnetosphere Ionosphere Coupling in the Solar System written by Charles R. Chappell and published by John Wiley & Sons. This book was released on 2016-10-31 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over a half century of exploration of the Earth’s space environment, it has become evident that the interaction between the ionosphere and the magnetosphere plays a dominant role in the evolution and dynamics of magnetospheric plasmas and fields. Interestingly, it was recently discovered that this same interaction is of fundamental importance at other planets and moons throughout the solar system. Based on papers presented at an interdisciplinary AGU Chapman Conference at Yosemite National Park in February 2014, this volume provides an intellectual and visual journey through our exploration and discovery of the paradigm-changing role that the ionosphere plays in determining the filling and dynamics of Earth and planetary environments. The 2014 Chapman conference marks the 40th anniversary of the initial magnetosphere-ionosphere coupling conference at Yosemite in 1974, and thus gives a four decade perspective of the progress of space science research in understanding these fundamental coupling processes. Digital video links to an online archive containing both the 1974 and 2014 meetings are presented throughout this volume for use as an historical resource by the international heliophysics and planetary science communities. Topics covered in this volume include: Ionosphere as a source of magnetospheric plasma Effects of the low energy ionospheric plasma on the stability and creation of the more energetic plasmas The unified global modeling of the ionosphere and magnetosphere at the Earth and other planets New knowledge of these coupled interactions for heliophysicists and planetary scientists, with a cross-disciplinary approach involving advanced measurement and modeling techniques Magnetosphere-Ionosphere Coupling in the Solar System is a valuable resource for researchers in the fields of space and planetary science, atmospheric science, space physics, astronomy, and geophysics. Read an interview with the editors to find out more: https://eos.org/editors-vox/filling-earths-space-environment-from-the-sun-or-the-earth