William H. Matthaeus

TL;DR: In this article, the coexistence of discrete modes and turbulence in numerical experiments of magnetohydrodynamics with a strong background magnetic field was studied, and it was shown that these modes could generate Alfven waves at discrete frequencies with values corresponding to solar g-modes and p -modes.

TL;DR: There have been more than 2000 refereed papers published using Cluster data but in this paper we will, of necessity, refer to only a small fraction of the published work as discussed by the authors.

TL;DR: In this paper, the authors show that time intervals originally thought to be outward propagating sometimes contain wave number bands in the cross helicity spectrum of inward propagating Alfvenic fluctuations.

Abstract: The magnetic and velocity field fluctuations in magnetohydrodynamic turbulence can be characterized by their directional alignment and induced electric field. These manifest as coherent spatial correlations which are measures of Alfvenicity and turbulence cascade strength, respectively. Solar wind observations and direct numerical simulations find that these distinctive correlations, caused by rapid relaxation processes that act to suppress nonlinearity, occur in localized spatial patches. This cellularization of magnetofluid turbulence is inconsistent with a superposition of Gaussian fields and could be related to spatial intermittency or other non-Gaussian statistics.

TL;DR: In this article, the in-plane Lorentz force and the out-of-plane magnetic field associated with the Hall electric field near the reconnection zone in the Swarthmore Spheromak Experiment (SSX) were measured.