Speaker
Description
Interplanetary shocks are fundamental agents of energy dissipation, particle
acceleration, and geomagnetic disturbance in the heliosphere, yet their complex
structure and geoeffective impacts are not fully understood. This study presents
a comprehensive investigation of interplanetary shock events using multi-spacecraft
observations from ACE, STEREO, Parker Solar Probe, and Solar Orbiter. Shocks
are identified through abrupt discontinuities in solar wind parameters, such as
magnetic field strength, plasma density, temperature, and velocity, with validation
performed using multi-spacecraft timing analysis to determine their propagation
direction and spatial extent. The Rankine-Hugoniot conservation relations are
systematically applied to compute key shock parameters, including shock normal
vectors, compression ratios, Alfvén Mach numbers, and the critical angle θBn,
enabling classification into quasi-parallel and quasi-perpendicular geometries.
Beyond shock characterization, the study examines associated interplanetary
structures, including Interplanetary Coronal Mass Ejection (ICMEs), sheath regions,
and magnetic clouds, to establish causal linkages between solar eruptions and shock
formation. Geoeffectiveness is assessed 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
across varying longitudinal separations, building on prior work identifying a 50%
probability cut-off 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 advances understanding of solar-terrestrial coupling and
enhances predictive capabilities for geomagnetic storm forecasting.
Keywords: Interplanetary Shocks. Multi-Spacecraft Observations. Rankine
Hugoniot Conditions. Geoeffectiveness. Interplanetary Coronal Mass Ejections.
Space Weather, Magnetic Clouds. Shock Parameters. Heliospheric Propagation.