Quasi-two-day wave influences on wave ducting and ionospheric disturbances over the Andes Lidar Observatory

The quasi-two-day wave (QTDW) is a planetary scale feature modulating winds and temperatures in the mesosphere and lower thermosphere (MLT) with a period of about 48 hours. In addition to affecting the MLT, the QTDW has been shown to induce oscillations in the ionosphere. The Atmosphere as a Sensor (AtmoSense) program seeks to better understand the process of energy propagating from the Earth surface upwards through the atmosphere. To this end, our team works to match signals from distinct instruments measuring different layers of the atmosphere. In this talk, I will discuss the results of one such effort centering around the effect of the QTDW on ducted waves in the MLT and ionospheric disturbances.

In our analysis of contemporaneous measurements over the Andes Lidar Observatory (ALO), we observe the QTDW at altitudes between ~80-100 km over the course of four days using both NAVGEM models. We see the same QTDW in background horizontal wind amplitude and direction spanning the full field of view (~700 x 700 km) of the ALO all-sky airglow imager. Simultaneously, we observe ducted waves spanning much of the airglow imaging field of view with horizontal wavelengths of 15-40 km. We see the same ducted waves in vertical winds measured by the ALO sodium lidar. The periods of strong wave ducting match periods of peak meridional winds from the QTDW. I will discuss the contribution from those background winds to the conditions leading to the observed ducting.

Furthermore, we have observed an interesting link between the QTDW phase and activity in the ionosphere. The strength and number of ionospheric disturbances measured by total electron content seems to be correlated with peaks in the QTDW wind amplitudes. We have expanded the geographic region we survey to much of northern South America and we have compared total electron content and QTDW winds over that region. I will discuss the results of these investigations.