ALBERT

Description: On May 12, 2021 the interplanetary counterpart of the May 9, 2021 coronal mass ejection impacted the Earth’s magnetosphere, giving rise to a strong geomagnetic storm. This work discusses the evolution of the various events linking the solar activity to the Earth’s ionosphere with special focus on the effects observed in the circumterrestrial environment. We investigate the propagation of the interplanetary coronal mass ejection and its interaction with the magnetosphere - ionosphere system in terms of both magnetospheric current systems and particle redistribution, by jointly analysing data from interplanetary, magnetospheric, and low Earth orbiting satellites. The principal magnetospheric current system activated during the different phases of the geomagnetic storm is correctly identified through the direct comparison between geosynchronous orbit observations and model predictions. From the particle point of view, we have found that the primary impact of the storm development is a net and rapid loss of relativistic electrons from the entire outer radiation belt. Our analysis shows no evidence for any short-term recovery to pre-storm levels during the days following the main phase.

Description: Over the last few years, the scientific community has made a significant effort to detect and interpret electromagnetic signals that might be related to seismic activity. Recent studies have shown how during or even before strong earthquakes the ionosphere shows characteristic electromagnetic interactions observed as plasma variations or electromagnetic (EM) emissions (both in the ELF and VLF bands). These EM emissions were detected both by ground-based [Pulinets and Boyarchuk 2004] and by space-based [Ouzounov et al. 2011, Pulinets and Ouzounov, 2011] instruments. However, a robust identification of such EM emissions should start from the definition of statistical distribution of the ionospheric electromagnetic (EM) waves energy in absence of seismic activity and other anomalous inputs (such as the ones derived by solar forcing). In this way, a background in the ionospheric EM emissions over seismic regions can be determined. Only after this step, a proper detection of an EM signal possibly correlated with the seismic activity can be accomplished: every EM signal which differs from the background (exceeding a statistically meaningful threshold) should be considered as a potential event to be investigated. Therefore, in this study, we performed a multiscale analysis of the ionospheric environmental background, using the entire CSES-01 (China Seismo-ElectroMagnetic Satellite) electric and magnetic field dataset (2018 - 2023), by creating the map of the averaged relative energy (εrel) over a 1° x 1° latitude-longitude cell, depending on both spatial and temporal scale of the ionospheric medium. The analysis was performed by means of the newly developed Fast Iterative Filtering (FIF) technique. Geomagnetic activity conditions are considered by the means of the Sym-H index in order to make a proper discrimination between external (atmospheric, ionospheric, magnetospheric, solar and cosmic activities) and internal (earthquakes, volcanoes) sources generating anomalous signals. Here we present the background obtained for various seismic regions and results obtained for some recent earthquakes.