An interdisciplinary review of recent advances in Alfvén wave research 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.

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.

The general background of this monograph and the aim of it is described in detail in Chapter I. As stated in 1.7 it is written according to the principle that "when rigour appears to conflict with simplicity, simplicity is given preference", which means that it is intended for a rather broad public. Not only graduate students but also advanced undergraduates should be able to understand at least most of it. This monograph is the result of many years of inspiring discussions with a number of colleagues, for which I want to thank them very much. Especially I should mention the groups in Stockholm and La Jolla: in Stockholm, Dr Carl-Gunne Flilthammar and many of his collaborators, including Drs Lars Block, Per Carlqvist, Lennart lindberg, Michael Raadu, Staffan Torven, Miroslav Babic, and Itlgvar Axniis, and further, Drs Bo Lehnert and Bjorn Bonnevier, all at the Royal Institute of Technology. Of other col leagues in Sweden, I should mention Dr Bertel Laurent, Stockholm University, Dr Aina Elvius, The Stockholm Observatory, and Dr Bengt Hultqvist, Kiruna. In La Jolla my thanks go first of all to Dr Gustaf Arrhenius, who once invited me to La Jolla, which was the start of a most interesting collaboration; further, to Dr W.B.

Heliophysics is a developing scientific discipline integrating studies of the Sun's variability, the surrounding heliosphere, and climatic environments. Over the past few centuries, our understanding of how the Sun drives space weather and climate on the Earth and other planets has advanced at an ever-increasing rate. This volume, the first in this series of three heliophysics texts, integrates such diverse topics for the first time as a coherent intellectual discipline. It emphasises the physical processes coupling the Sun and Earth, allowing insights into the interaction of the solar wind and radiation with the Earth's magnetic field, atmosphere and climate system. It provides a core resource for advanced undergraduates and graduates, and also constitutes a foundational reference for researchers in heliophysics, astrophysics, plasma physics, space physics, solar physics, aeronomy, space weather, planetary science and climate science. Additional online resources, including lecture presentations and other teaching materials, are accessible at www.cambridge.org/9780521110617.

Informal discussions in 1977 among a number of scientists asso ciated with solar and interplanetary physics revealed a need for a dialogue between the two often-divergent groups. It was clear that the latter group was dependent essentially on the sun for its raison d'etre. On the other hand it was also clear that the former group could benefit in its search for insight vis-a-vis solar activity by looking beyond the shell of the inner corona. Needless to add that the combined solar/interplanetary topic is relevant to astrophysics when one considers stellar winds and binary star flows. It was felt, there fore, that a symposium was essential to bring together, for the first time, leading solar and interplanetary physicists from the interna tional community to discuss and record herein their own research. The fundamental physical processes underlying our own capricious star's activity can be understood only by the coupling of solar and interplan etary topics in an intimate observational and theoretical structure. This book, intended for active research scientists and advanced grad uate students, is an important step in this direction. The background of solar and interplanetary dynamics is provided in Part I (The Life History of Coronal Structures and Fields) and Part II (Coronal and Interplanetary Responses to Long Time Scale Phenomena).

This book provides an overview of solar wind turbulence from both the theoretical and observational perspective. It argues that the interplanetary medium offers the best opportunity to directly study turbulent fluctuations in collisionless plasmas. In fact, during expansion, the solar wind evolves towards a state characterized by large-amplitude fluctuations in all observed parameters, which resembles, at least at large scales, the well-known hydrodynamic turbulence. This text starts with historical references to past observations and experiments on turbulent flows. It then introduces the Navier-Stokes equations for a magnetized plasma whose low-frequency turbulence evolution is described within the framework of the MHD approximation. It also considers the scaling of plasma and magnetic field fluctuations and the study of nonlinear energy cascades within the same framework. It reports observations of turbulence in the ecliptic and at high latitude, treating Alfvénic and compressive fluctuations separately in order to explain the transport of mass, momentum and energy during the expansion. Further, existing models are compared with direct observations in the heliosphere. The problem of self-similar and anomalous fluctuations in the solar wind is then addressed using tools provided by dynamical system theory and discussed on the basis of available models and observations. The book highlights observations of Yaglom’s law in solar wind turbulence, which is one of the most important findings in fully developed turbulence and directly related to the long-lasting and still unsolved problem of solar wind plasma heating. Lastly, it includes a short chapter dedicated to the kinetic range of fluctuations, which has recently been receiving more attention from the space plasma community, since this is inherently related to turbulent energy dissipation and consequent plasma heating. It particularly focuses on the nature and role of the fluctuations populating this frequency range, and discusses several model predictions and recent observational findings in this context.