Global Navigation Satellite System (GNSS) observations provide a powerful remote sensingframework for probing the coupled atmosphere–ionosphere system through measurementsof ionospheric and tropospheric propagation delays. In this seminar, I will present recentstudies utilizing GPS-derived Total Electron Content (TEC) and Integrated/PrecipitableWater Vapor (IWV/PWV) estimates to investigate a broad range of natural and anthropogenicphenomena, including solar flares, geomagnetic storms, flash floods, earthquakes, andballistic missile launches.Particular emphasis will be placed on the physical interpretation of ionosphericdisturbances associated with extreme space weather events and their temporal evolutionacross different spatial scales. In parallel, I will demonstrate how GNSS troposphericproducts can be used to monitor atmospheric moisture transport and rapidly evolvingmeteorological conditions related to severe weather and flash-flood-producing systems.The seminar will further explore emerging approaches that integrate artificial intelligence,statistical analysis, and multi-sensor electromagnetic observations to improve detectioncapability, reduce modeling uncertainty, and enhance understanding of coupled lithosphere–atmosphere–ionosphere interactions. These studies demonstrate the growingrole of GNSS remote sensing as a versatile tool for environmental monitoring, hazard assessment, and geophysical research.
