Speaker
Description
First name: Illya
Last nameL Plotnikov
All authors: Illya Plotnikov
Abstract: Powerful solar eruptions are known to produce fast and wide shock waves in the solar corona and inner heliosphere. The relationship between the coronal shock waves, solar energetic particles and different types of radio emission is a subject of long-lasting research activity. We perform a case study of 31 December 2023 eruption that occurred near eastern limb of the Sun. It produced a X5.0 class X-ray flare, a global EUV wave, a fast (>3000 km/s) Coronal Mass Ejection, strong radio emissions (including several type III and type II bursts), energetic particles in-situ, and high-energy gamma-ray emission of long duration. We employ a technique that combines the reconstructed coronal shock from observations with background coronal MHD simulations to produce shock-mediated synthetic radio spectrum, assuming local emission at plasma frequency (and harmonics). We show that transient high Mach number and quasi-perpendicular region at the flank of expanding coronal shock explains both a ‘hot flux tube’ precursor seen in EUV observations and reverse drifting radio spectral features observed by ground-based facilities. The occurrence of this evanescent strong shock patch was observed when it propagated across pseudo-streamer's cusp where the magnetic field was particularly low. We also find evidence that, at higher coronal altitudes, the low-frequency type II radio burst detected by several spacecraft, is triggered by the interaction of the shock with the Heliospheric Current Sheet.