KINETIC PLASMA TURBULENCE IN THE FAST SOLAR WIND MEASURED BY CLUSTER

Journal Article · Mon May 20 04:00:00 EDT 2013 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/769/1/58· OSTI ID:22126594

Roberts, O. W.; Li, X. ^[1]

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1. Institute of Mathematics and Physics, Aberystwyth University, Aberystwyth, Ceredigion SY23 3BZ (United Kingdom)

The k-filtering technique and wave polarization analysis are applied to Cluster magnetic field data to study plasma turbulence at the scale of the ion gyroradius in the fast solar wind. Waves are found propagating in directions nearly perpendicular to the background magnetic field at such scales. The frequencies of these waves in the solar wind frame are much smaller than the proton gyrofrequency. After the wavevector k is determined at each spacecraft frequency f{sub sc}, wave polarization property is analyzed in the plane perpendicular to k. Magnetic fluctuations have {delta}B > {delta}B{sub Parallel-To} (here the Parallel-To and refer to the background magnetic field B{sub 0}). The wave magnetic field has right-handed polarization at propagation angles {theta}{sub kB} < 90 Degree-Sign and >90 Degree-Sign . The magnetic field in the plane perpendicular to B{sub 0}, however, has no clear sense of a dominant polarization but local rotations. We discuss the merits and limitations of linear kinetic Alfven waves (KAWs) and coherent Alfven vortices in the interpretation of the data. We suggest that the fast solar wind turbulence may be populated with KAWs, small-scale current sheets, and Alfven vortices at ion kinetic scales.

• OSTI ID: 22126594
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 769; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
79 ASTRONOMY AND ASTROPHYSICS
FILTERS
FLUCTUATIONS
GYROFREQUENCY
MAGNETIC FIELDS
PLASMA
POLARIZATION
PROTONS
ROTATING PLASMA
SOLAR WIND
TURBULENCE