Universität zu Köln

Gerick, F., Saur, J. and von Papen, M. (2017). The Uncertainty of Local Background Magnetic Field Orientation in Anisotropic Plasma Turbulence. Astrophys. J., 843 (1). BRISTOL: IOP PUBLISHING LTD. ISSN 1538-4357

Full text not available from this repository.

Abstract

In order to resolve and characterize anisotropy in turbulent plasma flows, a proper estimation of the background magnetic field is crucially important. Various approaches to calculating. the background magnetic field, ranging from local. to globally averaged fields, are commonly used in the analysis of turbulent data. We investigate how the uncertainty in the orientation of a scale-dependent background magnetic field influences the ability to resolve anisotropy. Therefore, we introduce a quantitative measure, the angle uncertainty, that. characterizes the uncertainty of the orientation of the background magnetic field that. turbulent structures are exposed to. The angle uncertainty can be used as a condition to estimate the ability to resolve anisotropy with certain accuracy. We apply our description to resolve the. spectral anisotropy in fast solar wind data. We show that, if the angle uncertainty grows too large, the power of the turbulent fluctuations is attributed to false local magnetic field angles, which may lead to an incorrect estimation of the. spectral indices. In our results, an apparent robustness of the spectral anisotropy to false local magnetic field angles is observed, which can be explained by a stronger increase of power for lower frequencies when the scale of the local magnetic field is increased. The frequency-dependent angle uncertainty is a measure that can be applied to any turbulent system.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Gerick, F. UNSPECIFIED UNSPECIFIED UNSPECIFIED Saur, J. UNSPECIFIED UNSPECIFIED UNSPECIFIED von Papen, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-226193
DOI:	10.3847/1538-4357/aa767c
Journal or Publication Title:	Astrophys. J.
Volume:	843
Number:	1
Date:	2017
Publisher:	IOP PUBLISHING LTD
Place of Publication:	BRISTOL
ISSN:	1538-4357
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language SOLAR-WIND TURBULENCE; ELECTRON MAGNETOHYDRODYNAMIC TURBULENCE; STRONG IMBALANCED TURBULENCE; WAVE-VECTOR ANISOTROPY; ALFVENIC TURBULENCE; 1 AU; POWER SPECTRA; FLUCTUATIONS; SIMULATIONS Multiple languages Astronomy & Astrophysics Multiple languages
Refereed:	Yes
URI:	http://kups.ub.uni-koeln.de/id/eprint/22619