[P-EM11] Coupling Processes in the Atmosphere-Ionosphere System

[PEM11-22] Nonlinear interactions of planetary-scale MLT waves using multi-radar techniques

★Invited Papers

*Maosheng He¹, Jorge L. Chau¹, Jeffrey M. Forbes², Guozhu Li^3,4 (1.Leibniz Institute of Atmospheric Physics at the Rostock University, Kühlungsborn, Germany,, 2.Ann and H.J. SmeadDepartment of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA,, 3.Beijing National Observatory of Space Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China,, 4.College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China)

Keywords:the mesosphere and lower thermosphere region, planetary wave (PW) , tide, Gravity-Rossby waves, nonlinear interactions, meteor radar

The mesosphere and lower thermosphere (MLT) region is populated by a variety of planetary-scale waves. These waves have been investigated using ground- and space-based observations. Most of these studies were based on single-spacecraft or single-station techniques and therefore were subject to inherent spatiotemporal ambiguities. To overcome the spatiotemporal ambiguity, we collected MLT winds detected by specular meteor radars from multi-longitudinal sectors to resolve the horizontal scale of MLT waves. With the constraints of both frequency and zonal wavenumber, we detected, in different cases, migrating solar tides (at periods of 24hr, 12hr, …, 4hr), lunar tides (12.4hr), planetary wave (PW) normal modes (at periods of 28, 16, 10, 6 days), Gravity-Rossby waves (quasi-2-day waves, Q2DWs) and varieties of secondary waves of nonlinear interactions between tides and PWs. Specifically, the interactions occur between the 12hr migrating tide and PW normal modes, between four migrating tides and Q2DWs, and between PW normal modes and stationary PWs, which increase the variety of MLT waves significantly.