Quasilinear Wave "Reflection" Due to Proton Heating by an Imbalanced Turbulent Cascade

TL;DR

This paper explores how proton heating in imbalanced turbulence causes wave reflection in the solar corona, highlighting the need for nonlinear modeling to understand solar wind acceleration and ion observations.

Contribution

It introduces a quasilinear analysis of wave-particle interactions in the solar corona, revealing wave growth mechanisms and the importance of nonlinear effects.

Findings

Velocity-space proton transport leads to wave growth in the sunward direction.

Reflected waves grow to unphysical levels in quasilinear analysis, indicating nonlinear effects are needed.

Mechanism may explain minor ion observations and solar wind acceleration.

Abstract

We investigate the quasilinear effects of the resonant wave-particle interaction under conditions of imbalanced turbulent heating in the collisionless coronal hole. We find that velocity-space transport of protons from the heated part of the distribution leads to strong wave growth in the minority (sunward) direction. In the present quasilinear analysis, the "reflected" waves grow to unphysical levels, indicating the necessity of including nonlinear processes. This mechanism is likely to be important in development of the fast solar wind, and may explain the puzzling minor ion observations of Landi & Cranmer (2009).