RELAXATION PROCESSES IN SOLAR WIND TURBULENCE

Date

2014-06-27

Department

Program

Citation of Original Publication

Servidio, S., C. Gurgiolo, V. Carbone, and M. L. Goldstein. “Relaxation Processes in Solar Wind Turbulence.” The Astrophysical Journal Letters 789, no. 2 (June 2014): L44. https://doi.org/10.1088/2041-8205/789/2/L44.

Rights

This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
Public Domain Mark 1.0

Subjects

Abstract

Based on global conservation principles, magnetohydrodynamic (MHD) relaxation theory predicts the existence of several equilibria, such as the Taylor state or global dynamic alignment. These states are generally viewed as very long-time and large-scale equilibria, which emerge only after the termination of the turbulent cascade. As suggested by hydrodynamics and by recent MHD numerical simulations, relaxation processes can occur during the turbulent cascade that will manifest themselves as local patches of equilibrium-like configurations. Using multi-spacecraft analysis techniques in conjunction with Cluster data, we compute the current density and flow vorticity and for the first time demonstrate that these localized relaxation events are observed in the solar wind. Such events have important consequences for the statistics of plasma turbulence.