A new method for estimating global coronal wave properties based on their interaction with solar coronal holes

¹ Departament de Física, Universitat de les Illes Balears (UIB), 07122 Palma, Spain
e-mail: isabell.piantschitsch@uib.es
² Institute of Applied Computing & Community Code (IAC 3), UIB, Palma, Spain
³ Institute of Physics, University of Graz, Universitätsplatz 5, 8010 Graz, Austria

Received: 16 April 2020
Accepted: 15 June 2020

Abstract

Among the effects of interactions between global coronal waves (CWs) and coronal holes (CHs) is the formation of reflected and transmitted waves. Observations of such events provide us with measurements of different CW parameters, such as phase speed and intensity amplitudes. However, several of these parameters are provided with only intermediate observational quality, whereas other parameters, such as the phase speed of transmitted waves, can hardly be observed in general. We present a new method to estimate crucial CW parameters, such as density and phase speed of reflected as well as transmitted waves, Mach numbers and density values of the CH’s interior, by using analytical expressions in combination with the most basic and most accessible observational measurements available. The transmission and reflection coefficients were derived from linear theory and used to calculate estimations for phase speeds of incoming, reflected, and transmitted waves. The obtained analytical expressions were validated by performing numerical simulations of CWs interacting with CHs. This new method enables us to determine in a fast and straightforward way reliable CW and CH parameters from basic observational measurements which provides a powerful tool to better understand the observed interaction effects between CWs and CHs.