Nonlinear interaction of kinetic Alfvén waves and radio waves in the solar corona

Abstract

Abstract. This paper investigates the nonlinear interaction of short wavelength kinetic Alfvén waves (KAWs) with extraordinary (x-) and ordinary (o-) mode radio waves using two fluid magnetohydrodynamics. The focus is on the interaction of a preexistent KAW with an ordinary electromagnetic wave, giving rise to an extraordinary electromagnetic wave. The equation governing the time evolution of the amplitude of the excited x-mode is derived. The growth time of the x-mode wave is determined and the corresponding interaction distance is computed for active regions in the low corona and for high corona. The nonlinear coupling appears to be quite efficient for reasonable amplitudes of KAWs in the corona, B A /B 0 = 0.02-0.2. We suggest that this process provides a new possibility for the detection and remote sensing of coronal kinetic Alfvén waves by means of radio observations.

A review of solar type III radio bursts

“…Effects such as mode coupling due to magnetic fields (e.g. Zheleznyakov & Zlotnik, 1964), and scattering due to low-frequency waves (Wentzel, 1984;Melrose, 1989a), or kinetic Alfven waves (Sirenko et al, 2002) during propagation are certainly able to reduce the degree of polarisation but cannot explain why fully polarised emission is never seen. Wentzel (1984) therefore proposed that the emission was depolarised to some extent within the source region itself, and that this was inherent to the emission process.…”

The planetary–exoplanetary environment: A nonlinear perspective

“…Kinetic Alfvén waves have been observed by satellites in the Earth's magnetosphere and AKR source region, and play an important role in energy release and transport in the planetary-exoplanetary environment. Another nonlinear process (Sirenko et al, 2002) involving three-wave parametric interaction of kinetic Alfvén waves with ordinary-mode and extraordinary-mode radio waves was investigated for solar corona.…”

Anisotropic turbulence of kinetic Alfvén waves and heating in solar corona

“…The first coronal heating mechanism involving the role of solar magnetic field lines was proposed by Alfvén (1942) using Alfvén waves (AWs). Since then many theories were put forward to explain the coronal heating and solar wind acceleration (Marsch 2006;Sirenko et al 2002;Cranmer et al 2007;Cranmer 2009). Among them, two prominent theories are: heating by waves (Narain & Ulmschneider 1996;Hood et al 1997;Goossens 1994;Priest et al 2000;Poedts et al 1989;Ruderman 1999) and heating by flares or magnetic reconnection (Jain et al 2005;Hood et al 2009;Sturrock et al 1999;Cassak & Shay 2012).…”