Speaker
Description
Interplanetary shocks are fundamental agents of energy dissipation and particle acceleration in the heliosphere, playing a critical role in space weather phenomena that affect Earth's technological infrastructure. This study presents a comprehensive investigation of complex interplanetary shock events using multi-spacecraft observations to characterize their physical properties, associated structures, and geoeffective impacts across distinct interplanetary medium environments. The research utilizes in-situ plasma and magnetic field measurements from multiple missions including ACE, STEREO, Parker Solar Probe, and Solar Orbiter, enabling robust identification of shock events through comparative analysis across different heliospheric positions. Shock events are detected by examining abrupt discontinuities in solar wind parameters—magnetic field strength, plasma density, temperature, and velocity—with multi-spacecraft timing analysis employed to determine propagation directions and spatial extents. The Rankine-Hugoniot conservation relations are systematically applied to calculate key shock parameters including shock normal vectors, compression ratios, Alfvén Mach numbers, and the critical angle θBn between the upstream magnetic field and shock normal, allowing classification into quasi-parallel and quasi-perpendicular geometries. Beyond shock characterization, the investigation extends to the interplanetary structures driving these disturbances—interplanetary coronal mass ejections (ICMEs), sheath regions, and magnetic clouds—establishing causal linkages between solar eruptions and heliospheric shock formation. Geoeffectiveness assessment is performed by correlating shock arrival times at near-Earth spacecraft with geomagnetic indices (Dst and Kp), quantifying how specific shock characteristics influence magnetospheric disturbances. Statistical analysis of shock events across varying longitudinal separations, building upon previous work demonstrating a 50% probability cutoff at 90° angular separation, provides insights into shock front expansion and propagation evolution through the inner heliosphere. By integrating multi-point observations, theoretical shock physics, and space weather impact assessment, this research contributes to improved understanding of solar-terrestrial coupling and enhances predictive capabilities for geomagnetic storm forecasting, addressing the growing societal need for reliable space weather preparedness as technological system dependencies continue to increase.
Keywords: Interplanetary shocks, multi-spacecraft observations, Rankine-Hugoniot conditions, geoeffectiveness, interplanetary coronal mass ejections, space weather, magnetic clouds, shock parameters, heliospheric propagation