Seasonality of the Migrating Semidiurnal Tide in the Tropical Upper Mesosphere and Lower Thermosphere and Its Thermodynamic and Momentum Budget

Abstract This work uses the Specified Dynamics‐Whole Atmosphere Community Climate Model with Ionosphere/Thermosphere eXtension (SD‐WACCM‐X) to determine and explain seasonality of migrating semidiurnal tide (SW2) components tropical upper mesosphere lower thermosphere (UMLT) temperature, zonal wind, meridional wind. also quantifies aliasing due SW2 in satellite‐based tidal estimates. Results show that during equinox seasons, vertical profiles UMLT temperature zonal‐wind SW2’s amplitudes have a double‐peak structure while they, along meridional‐wind SW2, single‐peak their June solstice. Hough mode reconstruction reveals linear combination five modes cannot fully reproduce these features. Tendency analysis for adiabatic term, nonlinear advection term are important. For winds, classical terms, gravity wave drag our alias then indicate can induce an ∼60% zonal‐mean DW1 calculated from sampling like Thermosphere–Ionosphere–Mesosphere Energetics Dynamics satellite Aura satellite. concludes situ generation by wave–wave interaction and/or waves plays significant roles SW2. The further adds one simply assume is negligible.