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Abstract
Where and under what conditions the transfer of energy between electromagnetic fields and particles takes place in the solar wind remains an open question. We investigate the conditions that promote the growth of kinetic instabilities predicted by linear theory to infer how turbulence and temperature-anisotropy-driven instabilities are interrelated. Using a large dataset from Solar Orbiter, we introduce the radial rate of strain, a novel measure computed from single-spacecraft data, which we interpret as a proxy for the double-adiabatic strain rate. The solar wind exhibits high absolute values of the radial rate of strain at locations with large temperature anisotropy. We measure the kurtosis and skewness of the radial rate of strain from the statistical moments to show that it is non-Gaussian for unstable intervals and increasingly intermittent at smaller scales with a power-law scaling. We conclude that the velocity field fluctuations in the solar wind contribute to the presence of temperature anisotropy sufficient to create potentially unstable conditions.
Department
Space Science Center
Publication Date
11-12-2024
Journal Title
Journal of Plasma Physics
Publisher
Cambridge University Press (CUP)
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
Opie S, Verscharen D, Chen CHK, et al. Temperature anisotropy instabilities driven by intermittent velocity shears in the solar wind. Journal of Plasma Physics. 2024;90(6):905900602. doi:10.1017/S0022377824001375
Rights
© The Author(s), 2024. Published by Cambridge University Press
Comments
This is an open access article published by Cambridge University Press (CUP) in Journal of Plasma Physics in 2024, available online: https://dx.doi.org/10.1017/S0022377824001375