A scale-free analysis of magnetic holes in the solar wind

Magnetic holes are isolated intervals of depleted interplanetary magnetic field (IMF) strength on timescales of several seconds to several hours. These intervals have been seen as often as several times per day in the ecliptic and at high heliospheric latitudes from 1 AU to 5.4 AU. We present a scale-free statistical technique for identifying magnetic holes and evaluating their significance relative to turbulent fluctuations in the solar wind. We apply this technique in a comprehensive search for magnetic holes in the Wind and ACE magnetometer data streams through 2004. Using magnetic field and ion measurements on the Wind spacecraft, we present the first statistical study of magnetic hole plasma signatures on the kinetic scale and we present a comparison of magnetic holes as kinetic and microscale phenomena. Magnetic holes are shown to be pressure-balanced structures with similar properties on all scales. Temperature anisotropy measurements are combined with magnetic field measurements to give direct evidence that the mirror-mode instability in the solar wind is a likely source of magnetic holes. Two-satellite correlations between ACE and Wind indicate that magnetic holes are stationary with respect to the solar wind and elongated along the IMF.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Physics.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Stevens, M. L. (Michael Louis)

Advisor dc:contributor.advisor

• Alan J. Lazarus.

• Physics.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/39568

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/39568