Sundkvist D, Krasnoselskikh V, Shukla PK, Vaivads A, André M, Buchert S, Rème H. In situ multi-satellite detection of coherent vortices as a manifestation of Alfvénic turbulence.
Nature 2005;
436:825-8. [PMID:
16094363 DOI:
10.1038/nature03931]
[Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2005] [Accepted: 06/16/2005] [Indexed: 11/08/2022]
Abstract
Turbulence in fluids and plasmas is a ubiquitous phenomenon driven by a variety of sources-currents, sheared flows, gradients in density and temperature, and so on. Turbulence involves fluctuations of physical properties on many different scales, which interact nonlinearly to produce self-organized structures in the form of vortices. Vortex motion in fluids and magnetized plasmas is typically governed by nonlinear equations, examples of which include the Navier-Stokes equation, the Charney-Hasegawa-Mima equations and their numerous generalizations. These nonlinear equations admit solutions in the form of different types of vortices that are frequently observed in a variety of contexts: in atmospheres, in oceans and planetary systems, in the heliosphere, in the Earth's ionosphere and magnetosphere, and in laboratory plasma experiments. Here we report the discovery by the Cluster satellites of a distinct class of vortex motion-short-scale drift-kinetic Alfvén (DKA) vortices-in the Earth's magnetospheric cusp region. As is the case for the larger Kelvin-Helmholtz vortices observed previously, these dynamic structures should provide a channel for transporting plasma particles and energy through the magnetospheric boundary layers.
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