Rapid Conjugate Appearance of the Giant Ionospheric Lamb Wave in the
Northern Hemisphere After Hunga-Tonga Volcano Eruptions
Abstract
The explosive eruption of the Hunga-Tonga volcano in the southwest
Pacific at 0415UT on 15 January 2022 triggered gigantic atmospheric
disturbances with surface air pressure wave propagating around the globe
in Lamb mode. In space, concentric traveling ionosphere disturbances
(CTIDs) are also observed as a manifestation of air pressure acoustic
waves in New Zealand ~0500UT and Australia
~0630UT. As soon as the wave reached central Australia
~0800UT, CTIDs appeared simultaneously in the northern
hemispheres through magnetic field line conjugate effect, which is much
earlier than the arrival of the air pressure wave to Japan after 1100UT.
Combining observations over Australia and Japan between 0800-1000UT,
CTIDs with characteristics of phase velocities of 320-390 m/s are
observed, matching with the dispersion relation of Lamb mode. The
arrival of atmospheric Lamb wave to Japan later created in situ CTIDs
showing the same Lamb mode characteristics as the earlier arriving
CTIDs.