Ionospheric TEC variations during an intense geomagnetic storm on 11 May 2024

Abstract

On May 11, 2024, a severe geomagnetic storm occurred, causing significant disruptions to Earth’s magnetosphere and ionosphere. These storms, primarily caused by solar activity, are distinguished by variations in solar wind that increase energy flow from the Sun to Earth. The present research aims to analyze the latitudinal response of ionospheric Total Electron Content (TEC) during this event. The analysis is based on data collected from three different geographic locations: IISC (13.02°N, 77.57°E), POL2 (42.68°N, 74.69°E), and NOVM (55.03°N, 82.91°E). The electron density of the ionosphere is crucial for satellite-based communication and navigation systems. Geomagnetic storm strength is measured by the Kp-index and Disturbance storm time (Dst) index. During a geomagnetic storm and X-class flare of magnitude 5.89, a maximum Dst index of -412 nT and Kp index of 9 are observed during the storm day. TEC values increased at IISc during the storm period compared to quiet days, but decreased over POL2 and NOVM stations. A good correlation was observed between the observed TEC during a storm day and the predicted TEC by the IRI-2020 model over IISC and NOVM, while moderate correlation was observed over POL2.