Characteristics of plasma turbulence and radio emission from an interplanetary shock wave

¹ Institute of Solar-Terrestrial Physics, Russian Academy of Sciences, PO Box 291, Irkutsk, Russia e-mail: leden@iszf.irk.ru
² Space Sciences Laboratory, University of California, Berkeley, USA
³ Institute of Laser Physics, Russian Academy of Sciences, Irkutsk Branch, Russia

Received: 3 July 2007
Accepted: 6 October 2007

Abstract

Aims.We investigate the characteristics of energetic electron beams, plasma turbulence and radio emission from interplanetary shock waves.

Methods.Numerical calculations of spectra and Landau damping of hot plasma eigen oscillations in the magnetic field are used.

Results.It is shown that the longitudinal wave spectrum, excited in the solar wind plasma, extends with the increase of the refractive index n over range of values 10. This result allows us to explain the broad band of emission, the constant value of the average ratio of frequency-band to radio emission frequency from interplanetary shock wave fronts, and to estimate the electron beam density and amplitude of Langmuir waves at the shock. It is shown that a spectrum of radio emission is determined by the spectrum of Langmuir waves excited upstream of the interplanetary shock wave by heated electrons escaping from the shock wave front.