研究期間：10110~10207;Collectively referred to as the middle atmosphere, the Earth’s mesosphere and lower thermosphere region is dominated by global scale oscillations known as atmospheric tides and planetary waves. Though forced primarily in the troposphere and stratosphere, both types of oscillations have the capacity to propagate vertically across different atmospheric layers, and have been found in recent studies to be capable of driving variability at higher altitudes in the ionosphere and neutral thermosphere, with corresponding periodicities and longitudinal structure. Such oscillations thereby serve to couple the weather and climate of the lower atmosphere with the variability of near Earth space. In this study, we propose to examine the spatial and temporal variability of the dominant Sun-synchronous migrating tides in the middle atmosphere and ionosphere, to understand the degree to which such oscillations in the middle atmosphere can affect changes in the ionosphere. We will also examine the occurrence of ionospheric oscillations near multi-day planetary wave periodicities, to understand the long-term significance of middle atmospheric planetary wave coupling in driving ionospheric variability. Atmospheric models will also be utilized to understand the nature of the lower atmospheric sources driving planetary waves in the middle and upper atmosphere.