Samuel Ogunjo (Federal University of Technology Akure, Nigeria) wird auf unserem IAP-Kolloquium einen Vortrag zum Thema "Applications of nonlinear dynamics and chaos theory in geospace investigation" halten.

Zusammenfassung:

The geospace environment, including the Earth's upper atmosphere, ionosphere, and magnetosphere, exhibits behaviour that often appears erratic and unpredictable. Yet beneath this apparent disorder lies a rich mathematical structure that classical statistical methods cannot detect. This presentation explores how the tools of nonlinear dynamics and chaos theory, pioneered by Edward Lorenz in the 1960s, have transformed our understanding of the space environment that surrounds and sustains modern civilisation. Drawing on more than a decade of research, our work distinguishes chaos from mere randomness, framing it instead as deterministic sensitivity to initial conditions. We introduce the key analytical instruments through which chaos reveals itself and apply them to a range of geospace measurable variables and phenomena including Total Electron Content (TEC), the Dst and SYM-H geomagnetic indices, equatorial electrojet currents, and high-frequency radio wave propagation parameters. Across solar cycles spanning more than five decades, our findings reveal that geospace dynamics are unmistakably chaotic, that complexity varies systematically with solar activity, and that ionospheric current systems once thought independent are in fact dynamically coupled.  The applicability of the non-linear dynamics in the characterization of different layers of the mesosphere and lower thermosphere is introduced.  We present the status of the ongoing installation of the LoLa Meteor Radar in Nigeria.