Mediation of collisionless turbulent dissipation through cyclotron resonance

Trevor A Bowen; Stuart D Bale; Benjamin D G Chandran; Alexandros Chasapis; Christopher H K Chen; Thierry Dudok de Wit; Alfred Mallet; Romain Meyrand; Jonathan Squire

doi:10.1038/s41550-023-02186-4

Mediation of collisionless turbulent dissipation through cyclotron resonance

Nat Astron. 2024;8(4):482-490. doi: 10.1038/s41550-023-02186-4. Epub 2024 Jan 23.

Authors

Affiliations

¹ Space Sciences Laboratory, University of California, Berkeley, Berkeley, CA USA.
² Physics Department, University of California, Berkeley, Berkeley, CA USA.
³ Department of Physics & Astronomy, University of New Hampshire, Durham, NH USA.
⁴ Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO USA.
⁵ Department of Physics and Astronomy, Queen Mary University of London, London, UK.
⁶ LPC2E, CNRS and University of Orléans, Orléans, France.
⁷ International Space Science Institute, Bern, Switzerland.
⁸ Physics Department, University of Otago, Dunedin, New Zealand.

Abstract

The dissipation of turbulence in astrophysical systems is fundamental to energy transfer and heating in environments ranging from the solar wind and corona to accretion disks and the intracluster medium. Although turbulent dissipation is relatively well understood in fluid dynamics, astrophysical plasmas often exhibit exotic behaviour, arising from the lack of interparticle collisions, which complicates turbulent dissipation and heating in these systems. Recent observations by NASA's Parker Solar Probe mission in the inner heliosphere have shed new light on the role of ion cyclotron resonance as a potential candidate for turbulent dissipation and plasma heating. Here, using in situ observations of turbulence and wave populations, we show that ion cyclotron waves provide a major pathway for dissipation and plasma heating in the solar wind. Our results support recent theoretical predictions of turbulence in the inner heliosphere, known as the helicity barrier, that suggest a role of cyclotron resonance in ion-scale dissipation. Taken together, these results provide important constraints for turbulent dissipation and acceleration efficiency in astrophysical plasmas.

Keywords: Astrophysical plasmas; Solar physics.