Statistical Analysis of ∼100 Hz Whistler-mode Waves near the Moon Using ARTEMIS Observations

Abstract

Utilizing 11 yr of Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon’s Interaction with the Sun P1 and P2 observations from 2013 to 2023, we perform a comprehensive statistical analysis of ∼100 Hz whistler-mode waves near the Moon. The investigation focuses on waves in the unique lunar environment, characterized by the absence of a global magnetic field and the presence of localized crustal magnetic anomalies. We carefully investigate the spatial distribution, amplitude, and peak frequencies of these waves, including their dependence on solar wind speed (Vsw), dynamic pressure (Pdyn), and interplanetary magnetic field strength (Btot). The results show that the wave amplitudes are predominantly between 0.01 and 0.3 nT, with significant differences in the spatial distribution of the ∼100 Hz waves inside and outside the Earth’s magnetosphere. Magnetic connection to the lunar surface significantly enhances the wave occurrence rate, while strong crustal magnetic fields suppress it. Wave amplitude exhibits a positive correlation with Pdyn, and peak frequency increases with Btot. These obtained distribution features and dependencies of lunar ∼100 Hz whistler-mode waves are valuable to improve the current understanding of wave generation mechanisms and the underlying contribution of wave–particle interactions in the lunar plasma environment.