The past forty years of space research have seen a substantial improvement in our understanding of the Earth’s magnetosphere and its coupling with the solar wind and interplanetary magnetic ?eld (IMF). The magnetospheric str- ture has been mapped and major processes determining this structure have been de?ned. However, the picture obtained is too often static. We know how the magnetosphere forms via the interaction of the solar wind and IMF with the Earth’s magnetic ?eld. We can describe the steady state for various upstream conditions but do not really understand the dynamic processes leading from one state to another. The main dif?culty is that the magnetosphere is a comp- cated system with many time constants ranging from fractions of a second to days and the system rarely attains a steady state. Two decades ago, it became clear that further progress would require multi-point measurements. Since then, two multi-spacecraft missions have been launched — INTERBALL in 1995/96 and CLUSTER II in 2000. The objectives of these missions d- fered but were complementary: While CLUSTER is adapted to meso-scale processes, INTERBALL observed larger spatial and temporal scales. However, the number of papers taking advantage of both missions simul- neously is rather small.

The past forty years of space research have seen a substantial improvement in our understanding of the Earth’s magnetosphere and its coupling with the solar wind and interplanetary magnetic ?eld (IMF). The magnetospheric str- ture has been mapped and major processes determining this structure have been de?ned. However, the picture obtained is too often static. We know how the magnetosphere forms via the interaction of the solar wind and IMF with the Earth’s magnetic ?eld. We can describe the steady state for various upstream conditions but do not really understand the dynamic processes leading from one state to another. The main dif?culty is that the magnetosphere is a comp- cated system with many time constants ranging from fractions of a second to days and the system rarely attains a steady state. Two decades ago, it became clear that further progress would require multi-point measurements. Since then, two multi-spacecraft missions have been launched — INTERBALL in 1995/96 and CLUSTER II in 2000. The objectives of these missions d- fered but were complementary: While CLUSTER is adapted to meso-scale processes, INTERBALL observed larger spatial and temporal scales. However, the number of papers taking advantage of both missions simul- neously is rather small.

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

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 197. Many of the most basic aspects of the aurora remain unexplained. While in the past terrestrial and planetary auroras have been largely treated in separate books, Auroral Phenomenology and Magnetospheric Processes: Earth and Other Planets takes a holistic approach, treating the aurora as a fundamental process and discussing the phenomenology, physics, and relationship with the respective planetary magnetospheres in one volume. While there are some behaviors common in auroras of the different planets, there are also striking differences that test our basic understanding of auroral processes. The objective, upon which this monograph is focused, is to connect our knowledge of auroral morphology to the physical processes in the magnetosphere that power and structure discrete and diffuse auroras. Understanding this connection will result in a more complete explanation of the aurora and also further the goal of being able to interpret the global auroral distributions as a dynamic map of the magnetosphere. The volume synthesizes five major areas: auroral phenomenology, aurora and ionospheric electrodynamics, discrete auroral acceleration, aurora and magnetospheric dynamics, and comparative planetary aurora. Covering the recent advances in observations, simulation, and theory, this book will serve a broad community of scientists, including graduate students, studying auroras at Mars, Earth, Saturn, and Jupiter. Projected beyond our solar system, it may also be of interest for astronomers who are looking for aurora-active exoplanets.

The Magnetospheric Multiscale (MMS) mission is a multiple-spacecraft Solar-Terrestrial Probe designed to study the microphysics of magnetic reconnection, charged particle acceleration, and turbulence in key boundary regions of Earth's magnetosphere. These three processes, which control the flow of energy, mass, and momentum within and across plasma boundaries, occur throughout the universe and are fundamental to our understanding of astrophysical and solar system plasmas.