Exploring Magnetospheric Substorm Avalanche Dynamics: on Crackling Noise Nature

The dynamics of the Earth's magnetosphere/ionosphere system is remarkably complex, particularly in response to changes of the solar wind and interplanetary conditions. This interplay between the Earth's magnetic field and the solar wind generates a highly complex dynamics. The interaction between the interplanetary medium and the Earth's magnetosphere triggers significant changes within the magnetosphere/ionosphere system. These alterations can lead to various phenomena, including magnetospheric substorms, which exhibit an avalanche dynamics and scale-free energy dissipation. This complex behavior resembles crackling noise phenomena observed in certain physical systems. By examining the scaling properties of auroral electrojet AL-index bursts during these substorms, we have identified similarities with crackling noise in front propagation models. Furthermore, our investigation has unveiled a scaling function describing the avalanche profile of the AL-index, shedding light on the underlying mechanisms governing these bursty dynamics. These findings significantly contribute to our understanding of magnetospheric plasma sheet dynamics and the mechanisms behind the magnetospheric substorms. By linking the scale-free characteristics of these bursts to crackling noise behavior, we gain valuable insights into the underlying physics governing these complex phenomena within Earth's magnetosphere/ionosphere system.