Variability Study of the Effect of Geomagnetic Storm of May, 10th - 11th, 2024 on the H-Component of the Geomagnetic Field using Wavelet Power Spectrum

Abstract

The study investigated the variability of geomagnetic storms from May 10th – 11th 2024 in Sulari (Iceland), Sodankyla (Finland), Nurmijarvi (Finland), Lerwick (United Kingdom) and Eskdalemuir (United Kingdom) using Wavelet Power Spectrum (WPS). The geomagnetic storm is a disturbance that can disrupt satellite communications, navigation, power grid as well as human socio-economic activities. The geomagnetic disturbance of May 10th – 11th 2024 was caused by a Coronal Mass Ejection (CME). The impact of CME was observed by using Wavelet Power Spectrum (WPS) technique to study the storm H-component variation in greater detail by revealing the hidden patterns. This will lead to a deeper understanding of the storm-time at high latitude geomagnetic field variation. The geoelectric field, time derivatives of the North, East and vertical component of the geoelectric field across the selected stations were considered and modeled. Wavelet Power Spectrum (WPS) was employed to study the fluctuations during the geomagnetic storms and the Ultra-Low Frequency (ULF) from the stations. It was noted that the WPS frequencies range between 0.05Hz – 0.4Hz within the intervals of 16-44Hrs respectively with the average powers of 200mm2 – 2500mm2. It was observed from Eskdalemuir that there was concentration of peak power around 16-24hrs and 36- 44hrs within the frequency band range between 0.15-0.25Hz, Lerwick displayed high power regions within 26 – 32hrs and 38-44Hrs which is 200mm2-400mm2 with the frequency of 0.25Hz. Nurmijarvi revealed the power maxima around 14-16hrs and 26 – 28hrs respectively within exceeding power of 1500 -2500mm2 and frequency of 0.05 – 0.1Hz and Sodankyla and Sular depict the average power of 700mm2 – 900mm2 and 2500 mm2 respectively, the frequencies bands were noted as 0.15Hz and 0.05-0.15Hz at Sodankylä and Sulari. Overall, the results confirm that geomagnetic storm effects were strongest, most persistent, and broadband at high latitudes, while becoming weaker, shorter-lived, and narrower in frequency toward mid- and low-latitudes. These findings highlight the critical role of auroral observatories in capturing storm-time magnetosphere–ionosphere dynamics, while mid- and low-latitude stations reflect the attenuation of geomagnetic disturbances with distance from the auroral oval.