Global propagation of ionospheric disturbances associated with the 2022
Tonga Volcanic Eruption
Abstract
In this study, we use measurements from over 4,735 globally distributed
Global Navigation Satellite System (GNSS) receivers to track the
progression of travelling ionospheric disturbances (TIDs) associated
with the 15 January 2022 Hunga Tonga-Hunga Ha’apai submarine volcanic
eruption. We identify two distinct Large Scale TIDs (LSTIDs) and several
subsequent Medium Scale TIDs (MSTIDs) that propagate radially outward
from the eruption site. Within 3000 km of epicenter, LSTIDs of
>1600 km and ~1350 km wavelengths are
initially observed propagating at speeds of ~950 ms-1
and ~555 ms-1, before substantial slowing to
~600 ms-1 and ~390 ms-1, respectively.
MSTIDs with speeds of 200-400 ms-1 are observed for six hours following
eruption, the first of which comprises the dominant global ionospheric
response and coincides with the atmospheric surface pressure disturbance
associated with the eruption. These are the first results demonstrating
the global impact of the Tonga eruption on the ionospheric state.