This book offers an overview of solar physics with a focus on solar activity, particularly the activity cycle. It is known that solar activity varies periodically, but there are also phases of intermittency, such as the Maunder minimum, during which solar activity is very low or high over several decades. The book provides a brief introduction to chaos theory and investigates solar activity in terms of its chaotic behavior. It also discusses how intermittent phases of solar activity have affected and can affect Earth’s climate and long-term space weather, and reviews the underlying theories relating to the solar dynamo mechanism. Furthermore, each chapter includes references to scientific literature (review articles and papers) so that readers can delve deeper into the subjects covered. This richly illustrated book will appeal to a wide readership, and is also useful as a textbook for courses in solar physics and astrophysics.
This book is primarily concerned with the computational aspects of predictability of dynamical systems - in particular those where observations, modeling and computation are strongly interdependent. Unlike with physical systems under control in laboratories, in astronomy it is uncommon to have the possibility of altering the key parameters of the studied objects. Therefore, the numerical simulations offer an essential tool for analysing these systems, and their reliability is of ever-increasing interest and importance. In this interdisciplinary scenario, the underlying physics provide the simulated models, nonlinear dynamics provides their chaoticity and instability properties, and the computer sciences provide the actual numerical implementation. This book introduces and explores precisely this link between the models and their predictability characterization based on concepts derived from the field of nonlinear dynamics, with a focus on the strong sensitivity to initial conditions and the use of Lyapunov exponents to characterize this sensitivity. This method is illustrated using several well-known continuous dynamical systems, such as the Contopoulos, Hénon-Heiles and Rössler systems. This second edition revises and significantly enlarges the material of the first edition by providing new entry points for discussing new predictability issues on a variety of areas such as machine decision-making, partial differential equations or the analysis of attractors and basins. Finally, the parts of the book devoted to the application of these ideas to astronomy have been greatly enlarged, by first presenting some basics aspects of predictability in astronomy and then by expanding these ideas to a detailed analysis of a galactic potential.
The book surveys how chaotic behaviors can be described with topological tools and how this approach occurred in chaos theory. Some modern applications are included. The contents are mainly devoted to topology, the main field of Robert Gilmore's works in dynamical systems. They include a review on the topological analysis of chaotic dynamics, works done in the past as well as the very latest issues. Most of the contributors who published during the 90's, including the very well-known scientists Otto RAssler, Ren(r) Lozi and Joan Birman, have made a significant impact on chaos theory, discrete chaos, and knot theory, respectively. Very few books cover the topological approach for investigating nonlinear dynamical systems. The present book will provide not only some historical OCo not necessarily widely known OCo contributions (about the different types of chaos introduced by RAssler and not just the RAssler attractor; Gumowski and Mira's contributions in electronics; Poincar(r)'s heritage in nonlinear dynamics) but also some recent applications in laser dynamics, biology,
Atmosphere is a chaotic system. As such it is inherently unpredictable. The book applies chaos theory to understand and predict climate systems. Author presents a cell dynamical system model for turbulent fluid flows. The model envisages the irregular space-time fluctuations of the atmospheric flow pattern generated as a consequence of the superimposition of a continuum of eddies. The natural space-time variability is quantified in terms of the universal inverse power-law form of the statistical normal distribution. A range of possible applications of the cell dynamical system model for weather and climate system is discussed. The book provides a comprehensive reference material for scientists and academicians working in the field of atmospheric sciences and related topics.
Starting in 1995 numerical modeling of the Earth’s dynamo has ourished with remarkable success. Direct numerical simulation of convection-driven MHD- ow in a rotating spherical shell show magnetic elds that resemble the geomagnetic eld in many respects: they are dominated by the axial dipole of approximately the right strength, they show spatial power spectra similar to that of Earth, and the magnetic eld morphology and the temporal var- tion of the eld resembles that of the geomagnetic eld (Christensen and Wicht 2007). Some models show stochastic dipole reversals whose details agree with what has been inferred from paleomagnetic data (Glatzmaier and Roberts 1995; Kutzner and Christensen 2002; Wicht 2005). While these models represent direct numerical simulations of the fundamental MHD equations without parameterized induction effects, they do not match actual pla- tary conditions in a number of respects. Speci cally, they rotate too slowly, are much less turbulent, and use a viscosity and thermal diffusivity that is far too large in comparison to magnetic diffusivity. Because of these discrepancies, the success of geodynamo models may seem surprising. In order to better understand the extent to which the models are applicable to planetary dynamos, scaling laws that relate basic properties of the dynamo to the fundamental control parameters play an important role. In recent years rst attempts have been made to derive such scaling laws from a set of numerical simulations that span the accessible parameter space (Christensen and Tilgner 2004; Christensen and Aubert 2006).
The global climate of the Earth has significantly varied over the last millennia. On a regional scale, the climate has varied and does presently vary on many different time scales, leading to a continuously changing pattern of temperatures, humidity, precipitation, with important effects on the whole terrestrial biosphere. Physicist are interested in understanding the mechanism at work by gathering data and properly analysing them, by building theoretical models and, if possible, making predictions on the future evolution of the system. Along these lines, an important question is to understand the role of the solar forcing, in order to unravel the internal mechanisms of variability of the Earth's climate from the variable forcing of the Sun. On the other hand, one can learn about the past solar variability by reading into the terrestrial archives that provide us with proxy data on the history of both the Sun and the climate. Thus, realizing that the Sun and the Earth form a closely coupled system, where the variable properties of the former may affect in many subtle ways the behaviour of the latter, is an important step toward the understanding of both.This book is explicitly devoted to these issues. First, it is important to obtain reliable data from terrestrial archives, and to properly date the records that have been measured. The first part of the book is devoted to these crucial aspects, dealing with various types of proxy data and with the difficult issue of the dating of the records. Once obtained, the data has to be interpreted. This process nowadays relies upon a plethora of data analysis methods that explicitly take into account the nonlinear nature of the system and try to elucidate the dynamics and the main processes active in the measured system. The second part of the book is devoted to the issue of data analysis and prediction. Finally, once the data has been interpreted and analyzed, theoretical models have to be built describing the dynamics of the system considered. Due to the extreme complexity of the Sun/Earth system (as well as of its components, the Sun itself and the Earth's climate), drastic simplifications in the modelling efforts have to be accepted and one has to bear in mind that the models probably are nothing more than a pale image of the real dynamics. The third part of the book is devoted to the theoretical and numerical modelling of the solar and climatic variability, and of their complex interactions. This volume gives an up-to-date view of the present state of this field.
This textbook is aimed at newcomers to nonlinear dynamics and chaos, especially students taking a first course in the subject. The presentation stresses analytical methods, concrete examples, and geometric intuition. The theory is developed systematically, starting with first-order differential equations and their bifurcations, followed by phase plane analysis, limit cycles and their bifurcations, and culminating with the Lorenz equations, chaos, iterated maps, period doubling, renormalization, fractals, and strange attractors.
On August 2000 in the Lomonosov Moscow State University the first scientific conference dedicated to chaos in the real astronomical systems was held. The most prominent astrophysisists - specialist in the field of stochastic dynamics - attended the conference. A broad scope of the problems related to the observed manifes tations of chaotic motions in galactic and stellar objects, with the involvement of basic theory and numerical modeling, were addressed. The idea (not so obvious, as we believe, to many astrophysicists) was to show that, while great progress in the field of stochastic mechanics was accomplished, the science of chaos in actually observed systems is only just being born. Basically, the situation described prompted the organizers to hold the meeting in order to discuss chaotic processes in real systems. It seemed worthwhile to begin these introductory remarks with a brief descrip tion of some events that preceeded the conference. Since actually existing systems are the subject of the natural sciences, and in the latter experiments play the key role, we shall begin our account with the experimental results.
