Download or read book Simulation of the Interaction of the Solar Wind with the Earth s Magnetic Field written by G. G. Managadze and published by . This book was released on 1968 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 The Interaction of the Solar Wind with the Earth s Magnetic Field written by Gareth George John and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Interaction Between the Solar Wind and the Earth s Magnetic Field written by S. Frankenthal and published by . This book was released on 1964 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report consists of a study of the interaction between the solar wind and the earth's magnetic field, which takes into account: (1) the presence of an interplanetary magnetic field within the solar wind, and (2) the possibility that the solar wind may be penetrated by field lines emanating from the earth. The first part of the report (Chapters I-IV) contains a qualitative discussion of the field and flow patterns which may develop under the conditions stated above. The second part of the report explores two methods for the treatment of the MHD equations which govern the interaction, namely, expansion in spatial coordinates, and parametric expansions. The first method, which is suitable for local studies of the flow, is applied to the region in the immediate vicinity of the stagnation line behind the bow shock. The results of this treatment are embodied in a local field-flow pattern, which reveals several features which can be attributed directly to the presence of an interplanetary field within the solar wind, weak as those fields may be.

Download or read book Laboratory Simulation of Solar Wind Earth Interaction written by Donald L. Chubb and published by . This book was released on 1969 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: A laboratory simulation experiment of the interaction of the solar wind and the earth's magnetic filed is being conducted at Lewis Research Center of NASA.

Download or read book Introduction to Space Physics written by Margaret G. Kivelson and published by Cambridge University Press. This book was released on 1995-04-28 with total page 594 pages. Available in PDF, EPUB and Kindle. Book excerpt: All aspects of space plasmas in the Solar System are introduced and explored in this text for senior undergraduate and graduate students. Introduction to Space Physics provides a broad, yet selective, treatment of the complex interactions of the ionized gases of the solar terrestrial environment. The book includes extensive discussion of the Sun and solar wind, the magnetized and unmagnetized planets, and the fundamental processes of space plasmas including shocks, plasma waves, ULF waves, wave particle interactions, and auroral processes. The text devotes particular attention to space plasma observations and integrates these with phenomenological and theoretical interpretations. Highly coordinated chapters, written by experts in their fields, combine to provide a comprehensive introduction to space physics. Based on an advanced undergraduate and graduate course presented in the Department of Earth and Space Sciences at the University of California, Los Angeles, the text will be valuable to both students and professionals in the field.

Download or read book Interaction of the Geomagnetic Field with Northward Interplanetary Magnetic Field written by Shree Krishna Bhattarai and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of the solar wind with Earth's magnetic field causes the transfer of momentum and energy from the solar wind to geospace. The study of this interaction is gaining significance as our society is becoming more and more space based, due to which, predicting space weather has become more important. The solar wind interacts with the geomagnetic field primarily via two processes: viscous interaction and the magnetic reconnection. Both of these interactions result in the generation of an electric field in Earth's ionosphere. The overall topology and dynamics of the magnetosphere, as well as the electric field imposed on the ionosphere, vary with speed, density, and magnetic field orientation of the solar wind as well as the conductivity of the ionosphere. In this dissertation, I will examine the role of northward interplanetary magnetic field (IMF) and discuss the global topology of the magnetosphere and the interaction with the ionosphere using results obtained from the Lyon-Fedder-Mobarry (LFM) simulation. The electric potentials imposed on the ionosphere due to viscous interaction and magnetic reconnection are called the viscous and the reconnection potentials, respectively. A proxy to measure the overall effect of these potentials is to measure the cross polar potential (CPP). The CPP is defined as the difference between the maximum and the minimum of the potential in a given polar ionosphere. I will show results from the LFM simulation showing saturation of the CPP during periods with purely northward IMF of sufficiently large magnitude. I will further show that the viscous potential, which was assumed to be independent of IMF orientation until this work, is reduced during periods of northward IMF. Furthermore, I will also discuss the implications of these results for a simulation of an entire solar rotation.

Download or read book A Study of the Viscous Interaction Between the Solar Wind and Earth s Magnetosphere Using an MHD Simulation written by Robert Jeffrey Bruntz and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The solar wind interacts with Earth's magnetosphere largely through magnetic reconnection and a "viscous-like" interaction that is not fully understood. The ionospheric cross-polar cap potential ([phi]PC) component due to reconnection ([phi]R) is typically much larger than the viscous component ([phi]V) and very dynamic, making detailed studies of the viscous potential difficult. We used the Lyon-Fedder-Mobarry (LFM) magnetohydrodynamic (MHD) simulation to study the viscous potential by running LFM for a variety of solar wind density and velocity values and ionospheric Pedersen conductance ([sigma]P) values, but no solar wind magnetic field, so that [phi]PC was entirely due to the viscous interaction. We found that [phi]V increased with solar wind density, scaling as n0.439 (n in cm-3), and [phi]V increased with solar wind velocity, scaling as V1.33 (V in km s-1); these results were combined to create a formula for [phi]V in LFM, using a [sigma]P value that produces realistic potentials: [phi]V = (0.00431)n0.439V1.33 (in kV), which matches simulation results very well. [phi]V also varied inversely with [sigma]P, as predicted by previous theory. The form of this formula is similar to results from the Newell et al. [2008] empirical study, which tested a list of viscous coupling functions and found that n1/2V2 worked best (but did not create a formula to predict potentials, so actual viscous potential values could not be compared). The Bruntz et al. formula was also compared to LFM results from a run with real solar wind input, from the Whole Heliosphere Interval (WHI), which lasted from 20 March to 16 April 2008. LFM was first run with the full solar wind from the WHI, then with the same solar wind but zero interplanetary magnetic field (IMF), which meant that [phi]PC = [phi]V for that run. These runs were performed with the empirical ionospheric solver, using the average F10.7 flux value from the WHI as input. This empirical ionosphere is known to produce potentials that are higher than observations, so the output was scaled down to match the range of the Bruntz et al. formula with a scaling factor y = 1.542, which was found from 11 steady periods in the WHI. Those same periods were also used to calibrate the Newell et al. viscous scaling factor, turning it into a predictive formula: [phi]V = (6.39 x10-5)n1/2V2 (in kV). Both viscous potential formulas were compared to [phi]PC from the zero-IMF run, producing [phi]V values that were very close to the LFM [phi]PC values, differing in opposite ways in some places, but with essentially identical correlation coefficients. We also used the y factor to scale [phi]PC from the full-IMF LFM run down, then compared it to [phi]PC from the Weimer05 empirical model. The two matched well in the higher [phi]PC values, but the Weimer05 [phi]PC values reached a minimum "floor" value, while the LFM [phi]PC has no such floor, and so dropped much lower in some places. The fact that y scaled the full-IMF LFM down to match the Weimer05 values, even though y was derived from very different runs and conditions, is interpreted to support the idea that the cause of high LFM potentials is in the ionospheric conductivity, since y is derived from the higher-conductivity-based Bruntz et al. formula.

Download or read book A Three dimensional MHD Simulation of the Interaction of the Solar Wind with the Earth s Magnetosphere written by Tatsuki Ogino and published by . This book was released on 1984 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of the Geospace Response to Dynamic Solar Wind Using the Lyon Fedder Mobarry Global MHD Simulation written by Richard E. F. Bonde and published by . This book was released on 2019 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the wind from the Sun advances towards Earth, it interacts with Earth's magnetic field. This solar wind carries with it a magnetic field, called the interplanetary magnetic field (IMF). Energy and momentum are transferred from the solar wind to the geospace environment through two mechanisms: magnetic reconnection between the IMF and Earth's magnetic field and a viscous-like interaction. While magnetic reconnection is the dominant mechanism, there are times when the viscous interaction has a significant contribution. Previous studies using magnetohydrodynamic (MHD) simulations to study the viscous interaction have done so using steady state solar wind conditions. The solar wind is highly dynamic and can have considerable changes on the order of minutes. We use the Lyon-Fedder-Mobarry global MHD simulation to test the effect the viscous interaction has on the transpolar potential (TPP) with solar wind velocity fluctuations. The TPP is used as a proxy for the amount of coupling between the solar wind and Earth's magnetosphere. While fluctuations in the equatorial plane seem to have little or no effect on the TPP, fluctuations in the meridional plane cause variations in the TPP, even creating an asymmetry between the hemispheres. The response the TPP was proportional to the amplitude of the velocity oscillation but appears not to be affected by the frequency of oscillation. There is also a strong flow asymmetry in the magnetotail, which is flapping like a wind sock, in response to these solar wind variations. This creates a large sunward flow in one of the two tail lobes. The effect of solar wind fluctuations can also be tested on the response to the dayside magnetopause. The dayside magnetopause position, regarded as a critical space weather metric, is of great importance to satellite operators. Large-scale fluctuations in the solar wind can compress the magnetopause inward over satellites, exposing them to the hazardous conditions in the magnetosheath. Again, previous studies on the magnetopause position were conducted with steady state solar wind conditions. We ran LFM to gauge the response of the subsolar magnetopause during conditions similar to a high-speed stream (HSS), where there are large Alfvénic fluctuations and the dynamic pressure is relatively constant. The dayside magnetopause responds to these IMF variations in a type of "breathing" mode. The subsolar magnetopause exhibits a hysteresis-like effect, having a roughly constant response time to an IMF perturbation with constantly changing IMF conditions. In certain situations, the subsolar magnetopause position never relaxes to steady state values. This shows that when running MHD simulations, the time history of the solar wind must be taken into account. A HSS from 14-19 September, 2017 was simulated in LFM to see the response of the dayside magnetopause. To verify the actual position of the dayside magnetopause during this event, a series of THEMIS magnetopause crossings were used. The THEMIS crossings, along with the LFM results, were compared to empirical models of the magnetopause. These empirical models use instantaneous solar wind parameters to predict the position of the magnetopause and at times were predicted to over 1 RE from the actual magnetopause position. The work presented in this dissertation shows that to improve the accuracy of empirical models, the time history of the solar wind cannot be overlooked.

Download or read book Exploring the Solar Wind written by Marian Lazar and published by BoD – Books on Demand. This book was released on 2012-03-21 with total page 475 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book consists of a selection of original papers of the leading scientists in the fields of Space and Planetary Physics, Solar and Space Plasma Physics with important contributions to the theory, modeling and experimental techniques of the solar wind exploration. Its purpose is to provide the means for interested readers to become familiar with the current knowledge of the solar wind formation and elemental composition, the interplanetary dynamical evolution and acceleration of the charged plasma particles, and the guiding magnetic field that connects to the magnetospheric field lines and adjusts the effects of the solar wind on Earth. I am convinced that most of the research scientists actively working in these fields will find in this book many new and interesting ideas.

Download or read book Mars Magnetism and Its Interaction with the Solar Wind written by Daniel Winterhalter and published by Springer Science & Business Media. This book was released on 2004-07-20 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given that the question of an internal magnetic field is of fundamental importance to the understanding of Mars' formation and thermal evolution, and of the evolution of Mars' atmosphere, surprisingly few of the many spacecraft sent to Mars were equipped with instrumentation for such investigations. Of the 9 or so orbiters that have successfully archived Mars orbit, even if for a short period of time, only two have returned useful data about the magnetic field and about the plasma environment near Mars: The Phobos 2 spacecraft, and more recently, Mars Global Surveyor (MGS). With the discovery by MGS that Mars has large remnant magnetic field structures indicating an internal dynamo long extinct, the true nature of the past and present interaction between Mars and the solar wind comes, for the first time, into sharp focus. This work, detailing the integration and new interpretation of the MGS and Phobos results, is a primary reference for the researcher studying solar wind/planet interactions.

Download or read book Interaction of the Earth s Magnetic Field with the Solar Wind written by Richard M. Patrick and published by . This book was released on 1967 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma wind tunnel has been constructed with the goal of producing a collision free fully ionized stream of hydrogen in which stationary collision free shocks can be produced. Such a flow has been produced with a magnetic field buried in the flow with components both perpendicular and parallel to the flow direction. Stationary shock waves have been created in this flow by placing a magnetic dipole in the flow with its axis parallel to the flow direction. The flow geometry has been studied using magnetic and electric probes, along with photographs of the flow. The structure of shock waves in fully ionized hydrogen flow has been studied, and the thickness of the shock waves is equal to several ion gyro radii when the Alfven Mach number of the flow is between 2 and 3 and the angle of the B field with respect to the flow direction is between 45 and 80 degrees. Furthermore, oscillations in the B and E fields are seen to stand ahead of the main shock jump with frequencies larger than the ion gyro frequency. A crude estimate of the dissipation due to these oscillations upon the ionized flow in the shock indicates that these standing magnetohydrodynamic waves may account for the dissipation required for the shock jump conditions when the Alfven Mach number is between 1.5 and 3.

Download or read book Development of a Comprehensive Magnetohydrodynamic Model of Solar Terrestrial Interaction written by Stephen S. Stahara and published by . This book was released on 1988 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work relates to the preliminary development of a comprehensive, multi-level, 3-D magnetohydrodynamic model that seeks to describe the detailed, global interaction of the solar wind plasma and magnetic field with the Earth's geospace. The development of five separate advanced computational submodels of the complete interaction model involves approximately 42,000 lines of fortran source code. These submodels provide the capability for quantitatively simulating a variety of steady and unsteady phenomena associated with the solar wind-terrestrial environment interaction process to a degree previously unattainable. A number of these new developments have been incorporated into a core interaction submodel that can be structured to work in both a rapid warning mode for spacecraft protection as well as in a detailed scientific analysis mode for fundamental studies. The other submodels developed either simulate similar phenomena of the solar wind-terrestrial environment interaction process as the core interaction submodel but at a higher level of simulation accuracy or simulate additional interaction phenomena. (jhd).

Download or read book Improving the Understanding of Kinetic Processes in Solar Wind and Magnetosphere From CLUSTER to MMS written by Antonella Greco and published by Frontiers Media SA. This book was released on 2021-02-01 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Estimating a Planetary Magnetic Field with Time dependent Global MHD Simulations Using an Adjoint Approach written by Christian Nabert and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of the solar wind with a planetary magnetic field causes electrical currents that modify the magnetic field distribution around the planet. We present an approach to estimating the planetary magnetic field from in situ spacecraft data using a magnetohydrodynamic (MHD) simulation approach. The method is developed with respect to the upcoming BepiColombo mission to planet Mercury aimed at determining the planet's magnetic field and its interior electrical conductivity distribution. In contrast to the widely used empirical models, global MHD simulations allow the calculation of the strongly time-dependent interaction process of the solar wind with the planet. As a first approach, we use a simple MHD simulation code that includes time-dependent solar wind and magnetic field parameters. The planetary parameters are estimated by minimizing the misfit of spacecraft data and simulation results with a gradient-based optimization. As the calculation of gradients with respect to many parameters is usually very time-consuming, we investigate the application of an adjoint MHD model. This adjoint MHD model is generated by an automatic differentiation tool to compute the gradients efficiently. The computational cost for determining the gradient with an adjoint approach is nearly independent of the number of parameters. Our method is validated by application to THEMIS (Time History of Events and Macroscale Interactions during Substorms) magnetosheath data to estimate Earth's dipole moment.