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On the fractal nature of the magnetic field energy density in the solar wind

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Hnat, B., Chapman, Sandra C., Kiyani, K., Rowlands, G. (George) and Watkins, Nicholas W.. (2007) On the fractal nature of the magnetic field energy density in the solar wind. Geophysical Research Letters, Vol.34 . ISSN 0094-8276

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Official URL: http://dx.doi.org/10.1029/2007GL029531

Abstract

The solar wind exhibits scaling typical of intermittent turbulence in the statistics of in situ fluctuations in both the magnetic and velocity fields. Intriguingly, quantities not directly accessed by theories of ideal, incompressible, MHD turbulence, such as magnetic energy density, B2, nevertheless show evidence of simple fractal (self‐affine) statistical scaling. We apply a novel statistical technique which is a sensitive discriminator of fractality to the B2 timeseries from WIND and ACE. We show that robust fractal behaviour occurs at solar maximum and determine the scaling exponents. The probability density function (PDF) of fluctuations at solar maximum and minimum are distinct. Power law tails are seen at maximum, and the PDF is reminiscent of a Lévy flight.

Item Type:	Journal Article
Subjects:	Q Science > QB Astronomy
Divisions:	Faculty of Science > Physics
Library of Congress Subject Headings (LCSH):	Solar wind -- Statistical methods, Fractals, Solar magnetic fields
Journal or Publication Title:	Geophysical Research Letters
Publisher:	American Geophysical Union
ISSN:	0094-8276
Date:	2007
Volume:	Vol.34
Identification Number:	10.1029/2007GL029531
Status:	Peer Reviewed
Access rights to Published version:	Open Access
Funder:	Leverhulme Trust (LT), Particle Physics and Astronomy Research Council (Great Britain) (PPARC)
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URI:	http://wrap.warwick.ac.uk/id/eprint/3883