Perturbation electric and magnetic fields carry in excess of 10(exp10) to 10(exp12) W of electrical power between the magnetosphere and high-latitude ionosphere. Most of this power is generated by the solar wind. The ionosphere at large spatial and temporal scales acts as a dissipative slab which can be characterized by its height-integrated Pedersen conductivity sigma p, so that the power flux into the ionosphere due to a quasi-static electric field E is given by sigma (pE2) The energy transferred to the ionosphere by time-varying electromagnetic fields in the form of Alfven waves is more difficult to calculate because density and conductivity gradients can reflect energy. Thus, field resonances and standing wave patterns affect the magnitude and altitude distribution of electrical energy dissipation. We use a numerical model to calculate the frequency-dependent electric field reflection coefficient of the ionosphere and show that the ionosphere does not behave as a simple resistive slab for electric field time scales less than a few seconds. Time variation of spacecraft-measured high-latitude electric and perturbation magnetic fields is difficult to distinguish from spatial structuring that has been Doppler-shifted to a non-zero frequency in the spacecraft frame. However, by calculating the frequency-dependent amplitude and phase relations between fluctuating electric and magnetic fields we are able to show that low frequency fields (

Alfvén Waves Across Heliophysics Progress, Challenges, and Opportunities Alfvén waves are fundamental to the dynamics of space plasmas. Recent advances in our knowledge about Alfvén waves have come from several directions, including new space missions to unexplored heliospheric regions, sophisticated rocket campaigns in the auroral zone, enlarged magnetometer arrays and radar networks, and significant advances in computer modeling. Alfvén Waves Across Heliophysics: Progress, Challenges, and Opportunities is an interdisciplinary collaboration from different space science communities to review recent and current Alfvén wave research. Volume highlights include: Alfvén waves in the solar atmosphere Alfvén waves at the giant planets Alfvén waves at Mars Alfvén waves in moon-magnetosphere systems Alfvén waves in geospace Alfvén waves in the laboratory 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.

IAU Symposium 259 presents the first interdisciplinary, comprehensive review of the role of cosmic magnetic fields, involving astronomers and physicists from across the community. Offering both theoretical and observational topics ranging from Earth's habitability to the origin of the universe, this is an invaluable summary for researchers and graduate students.

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

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 118. The magnetosphere is an open system that interacts with the solar wind. In this system, solar wind energy continuously permeates different regions of the magnetosphere through electromagnetic processes, which we can well describe in terms of current systems. In fact, our ability to use various methods to study magnetospheric current systems has recently prompted significant progress in our understanding of the phenomenon. Unprecedented coverage of satellite and ground?]based observations has advanced global approaches to magnetospheric current systems, whereas advanced measurements of electromagnetic fields and particles have brought new insights about micro?]processes. Increased computer capabilities have enabled us to simulate the dynamics not only of the terrestrial magnetosphere but also the magnetospheres of other planets. Based on such developments, the present volume revisits outstanding issues about magnetospheric current systems.