Observations of the Fluctuations in the Interplanetary Magnetic Field around L1 Point during the Solar Transient Events of 2024 with MAG Payload on board Aditya-L1 Spacecraft

Abstract The magnetometer (MAG) payload on board India’s first solar mission, Aditya-L1, is a dual-sensor fluxgate magnetometer designed to measure the interplanetary magnetic field (IMF) while operating in a halo orbit around the first Sun–Earth Lagrangian point (L1). Since becoming operational in 2024 January, MAG has continuously recorded local magnetic field data and has captured several solar transient events over the past 1 yr. During these events, the IMF, typically around 5 nT, exhibited significant enhancements in magnitude. This study focuses on three such solar events observed in 2024 March, May, and October. Analysis of the magnetic field power spectra during these events reveals fluctuations consistent with Kolmogorov-type turbulence, characterized by a spectral slope close to −5/3. To emphasize changes in spectral behavior, the event-day spectra are compared with those from a day when the quiet solar wind conditions prevail. A marked contrast is observed: while the quiet periods exhibit anisotropic turbulence, the extreme events display quasi-isotropic behavior, with spectral slopes closely following the Kolmogorov spectrum across all three IMF components. The results, including detailed variations in spectral slope and turbulence characteristics, are presented and discussed in this paper.