Short-Term Tidal Modal Variability in the MLT Revealed by Combined ICON/MIGHTI and Meteor Radar Chain Observations

Atmospheric tides propagating upward from the lower atmosphere undergo nonlinear interactions and modulate ionospheric plasma redistribution, leading to pronounced day-to-day variability in ionospheric parameters. This variability reflects the superposition of multiple tidal components with different periods, zonal wavenumbers, and mode structures, yet the dominant modes remain unclear. A hybrid method that combines space-based observations (ICON/MIGHTI), ground-based measurements (Chinese meteor radar chain), and empirical tidal modes (ETMs) is applied to extract the short-term tidal variability. The method is validated during the 2021 sudden stratospheric warming event, capturing the enhancement of the SW2 tidal amplitude, a strengthened first antisymmetric mode, and the phase advance in E-region neutral winds. Future work will extend this approach to assess the modal contributions of tides to the variability of ionospheric plasma drift.