Dynamic Processes of the Moreton Wave on 2014 March 29

Abstract

Abstract On 2014 March 29, an intense solar flare classified as X1.0 occurred in active region 12017. Several associated phenomena accompanied this event, among them a fast-filament eruption, large-scale propagating disturbances in the corona and the chromosphere including a Moreton wave, and a coronal mass ejection. This flare was successfully detected in multiwavelength imaging in the Hα line by the Flare Monitoring Telescope (FMT) at Ica University, Peru. We present a detailed study of the Moreton wave associated with the flare in question. Special attention is paid to the Doppler characteristics inferred from the FMT wing (Hα ± 0.8 Å) observations, which are used to examine the downward/upward motion of the plasma in the chromosphere. Our findings reveal that the downward motion of the chromospheric material at the front of the Moreton wave attains a maximum velocity of 4 km s−1, whereas the propagation speed ranges between 640 and 859 km s−1. Furthermore, using the weak-shock approximation in conjunction with the velocity amplitude of the chromospheric motion induced by the Moreton wave, we derive the Mach number of the incident shock in the corona. We also performed the temperature-emission measure analysis of the coronal wave based on the Atmospheric Imaging Assembly observations, which allowed us to derive the compression ratio, and to estimate Alfvén and fast-mode Mach numbers on the order of 1.06–1.28 and 1.05–1.27. Considering these results and the magnetohydrodynamics linear theory, we discuss the characteristics of the shock front and the interaction with the chromospheric plasma.