[P-EM13] Coupling Processes in the Atmosphere-Ionosphere System

[PEM13-16] Delineating the tidal influence on the F-region using ICON during 2021

*Astrid I Maute¹、Chihoko Cullens²、Jeffrey Forbes²、Scott England³、Thomas Immel⁴ (1.National Center for Atmospheric Research、2.University of Colorado, Boulder、3.Virginia Tech、4.University of California, Berkeley)

キーワード：atmospheric tides, F-region ionosphere, model and observation

The dynamical forcing from the lower atmosphere via planetary waves and tides is highly variable and provides constant driving of the upper atmosphere. Depending on the background mesosphere-lower thermosphere conditions tides can dissipate, be modulated, propagate further upward, or interact with other waves and tides leading to a complex tidal spectrum. Tides are important for the ionospheric variability because they can imprint their signature on the plasma through e.g., the wind dynamo, F-region wind, and compositional changes. In addition, even during quiescent times the solar wind deposits energy into the upper atmosphere changing the atmosphere through which the tides propagate.
The Ionospheric Connection explorer (ICON) is designed to study the coupling between the lower atmosphere and space by observing among others low latitude neutral winds, temperature, ion drift and plasma characteristics. The numerical model TIEGCM supports the interpretation of the observations. In this study we want to isolate and quantify the tidal influence on the ion drift and plasma distribution in the F-region by conducting numerical experiments with and without tidal forcing. We will focus on some prevalent tides to characterize their change with the background atmosphere and tidal interactions especially during periods of moderate geomagnetic activity. We will set the simulation result in perspective to the ICON observations to evaluate the tidal influence on the F-region.