Longitudinal Response of the Low-latitude Ionosphere to 2017 Sudden Stratospheric Warming Event
Year: 2025
Type: article
Abstract: The Earth's ionosphere, a crucial region for communication and navigation systems, is susceptible to disturbances driven by both external (solar and geomagnetic activity) and internal (atmospheric waves) forces. These internal forces are known to be amplified during SSW events, creating significant ionospheric perturbations. This study investigates the longitudinal response of the low-latitude ionosphere, specifically focusing on the EIA, to the 2017 SSW event. Addressing a gap in current understanding, this research analyzes the longitudinal variations in TEC within the African and Asian sectors during the February 2017 SSW, aiming to provide a more comprehensive global perspective on SSW-ionosphere coupling. Previous findings have suggested longitudinal variations in EIA behavior, and this study seeks to provide concrete evidence of the SSW's longitudinal impact on the ionosphere through TEC data analysis. Using TEC data obtained from GPS observations, this study reveals a strong ionospheric response to the 2017 SSW event, characterized by irregular perturbations with large amplitudes, particularly in the African sector. During the peak phase of the SSW, ionospheric TEC perturbations begin just a day after the peak in stratospheric temperature and manifest as a suppression of the EIA for approximately 72 hours (3 days), indicative of a downward vertical drift. This suppression suggests a modulation of the fountain effect, which is further supported by the observed response of the mean zonal wind. The observed longitudinal differences in TEC perturbations, with stronger effects over the African sector compared to the Indian sector, highlight the influence of local effects on the ionospheric response to SSWs. These local effects could encompass variations in the geomagnetic field configuration, differences in the background ionospheric density and composition, and regional differences in atmospheric wave propagation and dissipation. Regional variations in tropospheric weather patterns and land-sea distribution can further affect the generation and propagation of atmospheric waves that couple the lower and upper atmosphere. The day to day TEC variations are discussed in the context of upward/downward E×B drift. Therefore, the observed longitudinal discrepancies underscore the importance of considering these local factors when assessing the impact of SSWs on the ionosphere and related technological systems. This study contributes to a more complete understanding of the complex interactions between the stratosphere and the ionosphere during SSW events and their implications for global communication and navigation infrastructure.
Institution: Abdullahi Fodio University of Science and Technology
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
SDG: Climate action
Open Access status: diamond
OpenAlex ID: W4408105910