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

Abstract

The solar migrating semidiurnal tide (SW2) is a westward propagating wavenumber-2 planetary-scale wave with a period of 12 hr. Studies have shown that the solar absorption of stratospheric ozone primarily generates SW2 (Chapman & Lindzen, 1970;Forbes & Garrett, 1979). Its long wavelength allows it to vertically propagate up to the ionosphere/thermosphere (I/T) region (Chapman & Lindzen, 1970). While it propagates, it has been shown to interact with the background atmosphere and/or atmospheric waves such as planetary-scale waves and gravity waves (