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Intermittency in space plasma turbulence

Abstract:

This chapter provides an overview on theoretical aspects and observational findings about intermittency in solar wind magnetohydrodynamic (MHD) turbulence. This phenomenon that became a remarkable topic in the past few years is because of the fact that solar wind fluctuations are neither isotropic nor scale-invariant, the two of the fundamental hypotheses at the basis of K41 Kolmogorov's theory. As a matter of fact, intermittency reflects in an inhomogeneous energy transfer during the turbulent cascade. In such conditions, time series alternate intervals of very high activity to intervals of quiescence. Primarily, this chapter introduces the problem of intermittency from a theoretical point of view, mentioning different models apt to reproduce the statistical features of turbulent intermittent behavior. It describes how intermittency affects solar wind parameters, how intermittency evolves with heliocentric distance from the sun, and how typical interplanetary events causing intermittency look like. © 2005 Elsevier B.V. All rights reserved.