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| Titel |
Evolution of turbulence through interplanetary shocks |
| VerfasserIn |
Alexander Pitna, Jana Safrankova, Zdenek Nemecek, Frantisek Nemec, Lubomir Prech, Christopher H. K. Chen, Georgy N. Zastenker |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250105177
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| Publikation (Nr.) |
 EGU/EGU2015-4630.pdf |
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| Zusammenfassung |
| The solar wind plasma is a turbulent medium in which Alfvenic MHD turbulence is assumed
to be a prime candidate for a transfer of large scale variations into smaller spatial scales, up to
the ion kinetic scale related to a thermal gyroradius or an ion inertial length. Interplanetary
shocks are naturally occurring in the solar wind and provide a unique opportunity to compare
a relatively quiet solar wind upstream with the shocked plasma downstream. The BMSW
instrument onboard the Spektr-R spacecraft has detected tens of interplanetary (IP) shocks in
a course of the 2011–2014 years. The high-time resolution (31Âms) of the ion flux,
density and solar wind speed measurements allows us to study spectral properties
in the transition region between MHD and kinetic scales. We have found that the
overall power of the ion flow fluctuations at all spatial scales increases roughly ten
times. The spectral slope of the power spectra in the kinetic range (3–8ÂHz) is
steeper downstream IP shocks than in the upstream solar wind. If the fluctuation
level increases the power law decay of ion kinetic structures gradually changes
to the exponential decay already reported for turbulence in interstellar plasmas. |
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