Global Winds Shape Planetary‐Scale Lamb Waves

Abstract

Abstract In 2022, the Hunga volcano eruption in Tonga generated atmospheric pressure waves that propagated globally and produced tsunamis in all the world's oceans. The largest pressure wave, with an amplitude of several hundred pascals, is the Lamb wave. Standard Lamb wave models, incorporating the sound‐speed as a function of temperature, satisfactorily explain observations in the near‐field but not in the far‐field. We show that an augmented Lamb wave model that includes the effects of wind and topography accurately reproduces the wavefronts observed by satellites and barometers, including those close to the antipode. Winds, first suggested to explain the travel times of Lamb waves from Krakatau in 1883, are now shown to also play a major role in shaping their waveforms; temperature and topography play smaller, but still detectable, roles. Our augmented model provides a significant advance for the development of early warning and hazard assessments for the meteotsunamis these waves produce.

Keywords

• Lamb wave
• meteotsunami
• global winds
• Earth topography
• satellites
• barometers