[P-EM06_1AM2] Study of coupling processes in Sun-Earth system with large radars and large-area observations

[PEM06-28] Study of the physical meanings of ionospheric tidal signatures using theoretical models

*Charles LIN¹, Yu-tsung CHEN¹, Po-cheng CHEN¹, Loren CHANG², Jia-ting LIN¹, Joseph HUBA³, Chia-hung CHEN¹ (1.Department of Earth Science, National Cheng-Kung University, Tainan, Taiwan, 2.Institute of Space Science, National Central University, Chung-Li, Taiwan, 3.Plasma Physics Division, Naval Research Laboratory, Washington, D.C., USA)

Keywords:atmospheric tides, tidal signature of ionospheric electron density

Variations the ionospheric electron density structures related to the tidal forcing propagating upward from the lower atmosphere have been studied intensively recently. The longitudinal variations of ionospheric electron density are related to the themospheric nonmigrating tidal signatures produced in-situ or propagating upward from below. During a stratospheric sudden warming, thermospheric migrating tidal signatures are modified and lead to the phase shift of ionospheric electron density structures at low latitudes. With the increasing number of global ionospheric observations, it is desirable to relate the thermospheric tidal signatures to corresponding tidal signatures of ionospheric electron density, since the neutral thermospheric temperature and wind observations are rather limited. In this paper we perform theoretical simulations to study the interconnections between tidal modes in thermospheric neutral parameters and ionospheric plasma. The migrating and nonmigrating tides of thermospehric winds output from NCAR GSWM/TIEGCM runs are incorporated to NRL SAMI-3 to investigate the responses of corresponding tidal modes in ionospheric electron density and their physical meanings.