Alina Bendt - Wave-packets and coherent structures in solar wind turbulence as seen by Solar Orbiter

Alina Bendt (University of Warwick) - The phenomenology of wave-packets and coherent structures across the turbulent cascade in the solar wind as seen by Solar Orbiter
Abstract:
Turbulence in the solar wind can contribute to its heating and impact its structure and dynamics. The Solar Orbiter mission offers in-situ measurements that enable the study of the evolution of this turbulence.
We use Solar Orbiter observations of homogeneous turbulence to determine under what conditions turbulent magnetic field fluctuations may be characterized as: (i) wave-packets and (ii) coherent structures. We perform the first systematic scale-by-scale decomposition of the magnetic field using two wavelets known to resolve wave-packets and discontinuities, the Daubechies 10 and Haar respectively. The comparison of wavelet decompositions uncovers three distinct behavioural regimes and identifies a crossover between wave-packet and coherent structure phenomena in the inertial and kinetic ranges. This crossover is seen to depend on solar wind parameters.
As coherent structures and wave-wave interactions are both candidates to mediate the turbulent cascade, these results offer new insights into the distinct physics of the inertial and kinetic ranges.
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