Magnetoseismology

Cold-ion populations and cold-electron populations are extremely difficult to measure in the Earth’s magnetosphere, and their properties, evolutions, and controlling factors are poorly understood. They are sometimes referred to as the “hidden populations”. But they are known to have multiple impacts on the behavior of the global magnetospheric system. These impacts include (a) the reduction of the dayside reconnection rate and consequently the reduction of solar-wind/magnetosphere coupling, (b) alteration of the growth rate and saturation amplitudes of plasma waves resulting in alterations of the energization rates of the radiation belts, (c) changes in plasma-wave properties resulting in changes in the loss rates of the ring current and radiation belts, (d) changes in the mass density of the magnetosphere resulting in changes in the radial diffusion of the radiation belts, (e) spatial and temporal structuring of the aurora, (f) altering magnetotail reconnection, (g) changing spacecraft charging, and (h) acting as sources for warm and hot magnetospheric populations. A recent workshop on the cold-particle populations of the magnetosphere inspired new work on the outstanding problems caused by a lack of understanding of those cold populations. This Research Topic will collect reports of that new work and will stimulate the formation of author teams to write review articles on what is known and what needs to be known. Commentaries assessing the present situation and guiding the research field into the future will be solicited from the community. Methods articles describing new measurement techniques and new spaceflight mission concepts will be welcomed.

Many approaches exist for scientific investigations and space research is no exception. The early approach during which each space plasma region within the Sun-Earth system was investigated separately with physics-based tools has now progressed to encompass investigations on coupling between these regions. Ample evidence now exists indicating the dynamic processes in these regions exhibit disturbances over a wide range of scales both in time and space. This new reckoning naturally leads to an emerging perspective of probing these natural phenomena with concepts and tools developed in modern statistical mechanics for physical processes governing the evolution of out-of-equilibrium and complex systems. These new developments have prompted a topical conference on Sun-Earth connection, held on February 9-13, 2004 at Kailua-Kona, Hawaii, USA, with the goal of promoting interactions among scientists practicing the traditional physics-based approach and those utilizing modern statistical techniques. This monograph is a product of this conference, a compilation of thirty-nine articles assembled into seven chapters: (1) multiscale features in complexity dynamics, (2) space storms, (3) magnetospheric substorms, (4) turbulence and magnetic reconnection, (5) modeling and coupling of space phenomena, (6) techniques for multiscale space plasma problems, and (7) present and future multiscale space missions. These articles show a diversity of space phenomena exhibiting scale free characteristics, intermittency, and non-Gaussian distributions of probability density function of fluctuations in the physical parameters of the Sun-Earth system. The scope covers the latest observations, theories, simulations, and techniques on the multiscale nature of Sun-Earth phenomena and underscores the usefulness in cross-disciplinary exchange needed to unravel the underlying physical processes, which may eventually lead to a possible unified description and prediction for space disturbances. * Extensive collection of state-of-the-art papers on multiscale coupling of Sun-Earth Processes * Present and future multiscale space missions * New techniques and models for performing multiscale analysis

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.

Remote-sensing observations have had a noteworthy impact on our knowledge of the structure and dynamics of these and many other boundary-layer phenomena. Ground based remote sensing techniques are both cheaper and less labor intensive than the alternative option of excavation, and given the current position some years after the introduction of PPG16, the use of geophysical survey as a pre-excavation component of archaeological investigation seems set to continue to expand. With the advent of modern satellite systems it will be possible within the next 20 years to observe important climate parameters remotely with unsurpassed time and spatial resolution. The future function of these systems is, to a large extent, dependent on today's development of detection techniques of climate parameters from ground-based remote sensing. Similarly, where climate parameters are already measured from space, their value is inevitably linked to accurate validation at the ground. Although geophysical surveying has been used for many years, the prediction of the potential success or failure of any method to identify archaeological remains is largely dependent upon much localized conditions. Magnetic susceptibility can be used to pinpoint areas where magnetometers are most likely to be successful, although it is quite possible to detect features even where the susceptibility is low, providing other factors are present.This comprehensive guide of magnetoseismology delivers the physics behind these movements and waves, and elucidates how to perceive and examine them. It also detailed the principles as used to remote sensing of near-Earth space and allied remote sensing systems. The role of ground-based remote sensors in boundary-layer research is reviewed, emphasizing the contributions of radars, sodars, and lidars aimed at the determination of optical and physical properties of aerosols and clouds as well as at the assessment of the general atmospheric state parameters (temperature, wind, moisture).This novel edition will be of interest to practitioners and researchers in physics of the Earth's magnetosphere and ionosphere, along with students, academics and scientifically well-educated laypersons with a curiosity in understanding space weather procedures and how these associated to the dynamic behavior of near-Earth space.

Provides the latest summary on the solar coronal heating enigma and magneto-seismology of the solar atmosphere, for solar physics researchers.

Written by a researcher at the forefront of the field, this first comprehensive account of magnetoseismology conveys the physics behind these movements and waves, and explains how to detect and investigate them. Along the way, it describes the principles as applied to remote sensing of near-Earth space and related remote sensing techniques, while also comparing and intercalibrating magnetoseismology with other techniques. The example applications include advanced data analysis techniques that may find wider used in areas ranging from geophysics to medical imaging, and remote sensing using radar systems that are of relevance to defense surveillance systems. As a result, the book not only reviews the status quo, but also anticipates new developments. With many figures and illustrations, some in full color, plus additional computational codes for analysis and evaluation. Aimed at graduate readers, the text assumes knowledge of electromagnetism and physical processes at degree level, but introductory chapters will provide an overview of the relevant plasma physics and magnetospheric physics. The book will thus be of interest to entry-level and established researchers in physics of the Earth's magnetosphere and ionosphere, as well as to students, academics and scientifically literate laypersons with an interest in understanding space weather processes and how these relate to the dynamic behavior of near-Earth space.