Periodic-chaotic alternating regimes during a fast solar metric-radio pulsation event

Abstract

Abstract In the magnetically dominated corona, loop-like structures are expected to undergo pulsating events which are highly structured in time and classified into different types from strictly periodic to irregular. In the case of periodic pulsations, they differ in their characteristic period: from tens of minutes (associated with global large-scale structure oscillations) to milliseconds (fast oscillations associated with a small local scale). These pulsations are strongly related to the basic physical properties of the solar corona and the evolution of magnetic loop-like structures that make up the entire solar atmosphere. This contribution describes a real-world scenario where a route to chaos and reverse processes take place. We examine the dynamic characteristics of a group of a train of pulsations at metric waveband solar radio emission as it evolves in time. The associated time series was recorded with the radio polarimeter of the INAF Trieste Astronomical Observatory, Basovizza Station on April 17, 2002, with a resolution time of 10 ms. Possible scenarios and mechanisms for the observed deterministic-chaos alternating regimes are discussed.