Opie, Simon;
Verscharen, Daniel;
Chen, Christopher HK;
Owen, Christopher J;
Isenberg, Philip A;
Sorriso-Valvo, Luca;
Franci, Luca;
(2024)
Temperature anisotropy instabilities driven by intermittent velocity shears in the solar wind.
Journal of Plasma Physics
, 90
(6)
, Article 905900602. 10.1017/S0022377824001375.
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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.
| Type: | Article |
|---|---|
| Title: | Temperature anisotropy instabilities driven by intermittent velocity shears in the solar wind |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1017/S0022377824001375 |
| Publisher version: | https://doi.org/10.1017/s0022377824001375 |
| Language: | English |
| Additional information: | This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited. Copyright Copyright © The Author(s), 2024. Published by Cambridge University Press |
| Keywords: | Science & Technology, Physical Sciences, Physics, Fluids & Plasmas, Physics, space plasma physics, plasma instabilities, plasma nonlinear phenomena, EXTENDED SELF-SIMILARITY, SCALING LAWS, TURBULENCE, PROTON, FLUID, DISSIPATION, EQUATION |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10203140 |
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