On January 15, 2022, we observed various unusual atmospheric wave events over the South American sector: Atmospheric pressure waves (Lamb mode) around 12:30 to 17:30 UT, Tsunamis along the Chile coast at around 17:00 to 19:00 UT, and related ionospheric disturbances between 11:30 and 20:00 UT. We understand that these events were generated by the Tonga volcanic eruption that occurred at (20.55°S, 175.39°W) in South Pacific Ocean at 04:15 UT. Several Traveling Ionospheric Disturbances (TIDs) were observed before and after the Lamb wave passed over the continent and the arrival of the tsunami on the Chile coast. This is the first time to report the signature of ionospheric disturbances over the South American continent generated by both the Lamb wave and the tsunami that were produced by the huge volcanic eruption.

Nighttime airglow images observed at the low-latitude site of São João do Cariri (7.4S, 36.5W) showed the presence of a medium-scale atmospheric gravity wave (AGW) associated with the 21 August 2017 total solar eclipse. The AGW had a horizontal wavelength of ~1,618 km, observed period of ~152 min and propagation direction of ~200 clockwise from the north. The spectral characteristics of this wave are in good agreement with theoretical predictions for waves generated by eclipses. Additionally, the wave was reverse ray-traced and the results show its path crossing the Moon’s shadow of the total solar eclipse in the tropical North Atlantic ocean at stratospheric altitudes. Investigation about potential driving sources for this wave indicate that the total solar eclipse as the most likely candidate. The optical measurements were part of an observational campaign carried out to detect the impact of the August 21 eclipse in the atmosphere at low latitudes.

An interesting interaction between equatorial plasma bubbles (EPBs), medium-scale traveling ionospheric disturbance (MSTID), and midnight brightness wave (MBW) were observed at Cachoeira Paulista, Brazil (22.7°S, 45.0°W, magnetic dip latitude ~20°S) by all-sky images of OI 630 nm emission, on the night of September 17-18, 2015. The EPBs were observed moving eastward while the MSTID propagated northwestward with the wavefront aligned to southwest-northeast. The MBW was observed propagating to south-southwest. After interaction with MSTIDs, the EPBs tilted and became larger and narrower. This effect could be associated with the x drift and also with changes in the neutral wind. Furthermore, the MBW also interacted with EPB and filled the EPB edge with plasma.