Wide-spectrum slow magnetoacoustic waves in coronal loops

Physics Department, University of Warwick, Coventry, CV4 7AL, England, UK

Corresponding author: David Tsiklauri, tsikd@astro.warwick.ac.uk

Received: 25 July 2001
Accepted: 27 September 2001

Abstract

A model interpreting variations of EUV brightness upward propagating in solar coronal loops as slow magnetoacoustic waves is developed. A loop is considered to have a non-zero plane inclination angle and offset of the circular loop centre from the baseline. The model also incorporates effects of dissipation and gravitational stratification. A linear evolutionary equation is derived and applied to investigations of slow wave dynamics. Both the non-zero plane inclination and the offset decrease the growth of the wave amplitude due to stratification. It is shown that wide-spectrum slow magnetoacoustic waves, consistent with currently available observations in the low frequency part of the spectrum, can provide a rate of heat deposition sufficient to heat the loop. In this scenario, the heat would be deposited near the loop footpoints, which agrees with the current observational data.