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| Titel |
Turbulence in the Solar Wind - a Model for Dissipation by Kinetic Alfvén-waves |
| VerfasserIn |
Anne Schreiner, Joachim Saur |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250087720
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| Publikation (Nr.) |
 EGU/EGU2014-1778.pdf |
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| Zusammenfassung |
| We investigate the dissipation of solar wind turbulent fluctuations by kinetic Alfvén waves
and the resultant spectral structure. Magnetic power spectra in the solar wind are
characterized by the following spectral ranges: An inertial range with a spectral index of 5/3
followed by a steeper range with a variable index, which has an average value of 8/3. Recent
Cluster observations show a second spectral break at electron scales and a subsequent
dissipation range. Results found by Sahraoui et al. (2009) point to a third power law with a
spectral index around 4 in this range. In contrast, observations by Alexandrova et al. (2009)
indicate an exponential decay in the dissipation range. The behavior of this small scale
cascade and a possible dissipation mechanism are still subjects of recent research. The aim of
our study is to describe these observations with a simple model and to investigate the
physical mechanism of the dissipation in the solar wind. Our model contains a
combination of two processes to describe the magnetic spectrum: An energy transport
model from large to small scales and a dissipation model, which extracts energy
from the magnetic field fluctuations. As a dissipation model, we use the imaginary
part of the kinetic Alfvén wave frequency from an appropriate dispersion relation. |
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