Ionospheric Irregularities Coinciding With the 2023 Typhoon Saola: A Multi-Instrument Study

Abstract

Typhoons exert significant influences on the ionosphere through atmospheric waves, ultimately affecting radio signals in the L-band of the Global Navigation Satellite System (GNSS). Due to the limitations of ground observations, the mechanisms and full impacts of typhoon-induced ionospheric variation remain to be explored. To address this gap, we embarked on a challenging expedition, employing a shipborne ionospheric scintillation monitoring receiver (ISMR) to gather data near the trajectory of Typhoon Saola during August and September 2023. The results revealed prominent amplitude scintillation and total electron content fluctuations in GNSS satellite detections, particularly during sunset from 29 to 31 August 2023. The findings are cross-validated with ground GNSS stations, high-frequency radar and the Swarm satellite, confirming the presence of equatorial plasma bubbles (EPBs). These EPBs have demonstrable effects on GNSS signals, ultimately influencing the precision of positioning performance. By examining the influence of the neutral wind field on atmospheric gravity waves triggered by typhoons, we elucidated how these waves impact the ionosphere, ultimately leading to the formation of plasma bubbles.