Solar and lunar ionospheric electrodynamic effects during stratospheric sudden warmings

摘要: Both solar and lunar atmospheric tides are believed to drive ionospheric electrodynamic effects during stratospheric sudden warmings (SSWs), but their relative importance is not well understood. In this study, long-term records (1958–2007) of the geomagnetic field analyzed determine average (S) (L) current systems for SSW non-SSW periods. It found that L intensity enhanced SSWs approximately by 75%, while change in S much smaller (~10%). Nonetheless, absolute changes comparable intensities. At magnetic equator, semidiurnal perturbations produced currents reinforce or cancel each other depending on phase moon, creating lunar-dependent recurrent onset total effect. These results indicate both contributions need be considered understand variability SSWs.