At https://phys.org/news/2023-05-eruption-tonga-underwater-volcano-disrupt.html … it’s good that scientists have been able to study the effects of the Tonga underwater volcano, producing reams of fascinating information. We now have a study in Scientific Reports  at https://doi.org/10.1038/s41598-023-33603-3 … which can be downloaded in full, that says an air pressure wave triggered by the eruption produced an equatorial plasma bubble in the ionosphere – disrupting satellite communications. The ionosphere is in the upper atmosphere. It is ionised by solar radiation, creating positively charged ions. However, they also note a surprising discovery. The ionosphere disturbances were observed several minutes to hours prior to the actual arrival of the shock wave triggered by the Tonga volcanic eruption, according to the Japanese researchers – politely. This suggests, they say, the idea that ionospheric disturbances only happen after such an eruption, needs revising. One may wonder if the ionospheric plasma bubble had an effect in the opposite direction – triggering the eruption. They do not go that far and suggest, instead, fast atmospheric waves arrival prior to the shock wave. The formation of the plasma bubbles at high altitude are rare – so this is a very unusual phenomenon. Indeed, the waves reached space, even beyond the ionosphere. They go on to say researchers need to pay attention to the connection between the ionosphere and the cosmosphere.