Hidden Gravity Waves Ahead of Storm Fronts May Warn of Meteorological Tsunamis

Some of the ocean’s most destructive waves never come from earthquakes. They are born in the sky. Meteorological tsunamis, also called meteotsunamis, are tsunami-like sea-level oscillations driven not by seismic rupture but by rapid changes in atmospheric pressure and wind as storms sweep across coastal waters. A new study published in the journal Natural Hazards by S. N. Kulichkov, I. P. Chunchuzov and colleagues examines a subtle but potentially decisive piece of this puzzle: the wave signals that arrive in the atmosphere before an atmospheric front itself. Drawing on long-term measurements of atmospheric pressure fluctuations recorded by a network of microbarographs in the Moscow region, the researchers investigated whether the early wave precursors of fronts, particularly atmospheric gravity waves, carry information about the strength of the pressure disturbances that fronts later deliver, and whether those disturbances are powerful enough to set the sea in destructive motion.

The physical setting of the study is the lower atmosphere over central Russia, where a distributed array of sensitive microbarographs continuously registers minute variations in surface pressure. Instruments of this kind are designed to detect pressure oscillations far smaller than the everyday rise and fall associated with passing weather systems, allowing researchers to resolve the fine structure of disturbances that would otherwise be lost in synoptic-scale records. By analyzing data collected over many years, the team characterized the properties of the wave precursors that precede atmospheric fronts, including their amplitudes, their frequency spectra, the spatial coherence of the signals across the network, and the speeds at which they propagate. These quantities matter because they describe not just that a wave exists, but how organized and energetic it is, which in turn reflects the dynamical processes unfolding within the approaching front.

Atmospheric fronts are boundaries between air masses of different temperature and density, and their motion is anything but smooth. As a front develops, processes known collectively as frontogenesis generate internal gravity waves, oscillations in which parcels of air are displaced from equilibrium and restored by buoyancy, propagating through the stratified atmosphere. Earlier theoretical and observational work, cited by the authors, established that jets and fronts are prolific sources of such waves, and that convective storms and thunderstorms also radiate gravity waves and infrasound into the lower atmosphere. The new study builds on this foundation by treating the gravity waves ahead of a front not as a curiosity but as a measurable precursor, a signal that arrives ahead of the main pressure jump and may encode information about the front’s eventual intensity.

The central empirical result of the paper is a relationship linking the amplitude of the atmospheric pressure disturbances observed in wave precursors to the amplitude of the peak pressure disturbances that characterize the fronts themselves. In other words, by measuring the gentle undulations in surface pressure that precede a front, the researchers found it is possible to estimate how large the sharp pressure jump delivered by the front will be. This kind of empirical connection is valuable because it converts a passive observation, the background of gravity-wave activity, into a predictive quantity. A monitoring station that registers growing precursor amplitudes gains an early, physically grounded indication that a strong front, capable of producing significant pressure perturbations at the surface, is on its way.

Why does the strength of a front’s pressure perturbation matter for the ocean? The answer lies in a mechanism described nearly a century ago by the mathematician Joseph Proudman, whose work on the effects of atmospheric pressure changes on the sea remains foundational. When a pressure disturbance moves across a water body at a speed that matches the speed of long ocean waves in that basin, a resonant coupling occurs. Each successive patch of low or high pressure pumps additional energy into the sea-level oscillation it drags along, and the response of the water can grow far beyond what a static pressure change alone would produce. This process, known as Proudman resonance, is the standard explanation for how modest atmospheric disturbances can generate sea-level waves with destructive power when they reach the shallow coastal zone, where the waves slow, compress and amplify.

Meteotsunamis occupy the same frequency band as earthquake-generated tsunamis, typically periods of minutes to a couple of hours, which makes them especially insidious. Coastal warning systems tuned to seismic events may not recognize the atmospheric origin of the threat, and the waves can strike harbors, bays and inlets where their energy is focused by the local geometry. Documented events in the Mediterranean, the Balearic Sea, the Adriatic, the Black Sea, the straits of western North America and elsewhere have caused flooding, damage to vessels and infrastructure, and occasional casualties. Researchers including Monserrat, Vilibić and Rabinovich, whose work the new paper cites, have catalogued these atmospherically induced destructive ocean waves and identified the combination of ingredients they require: a fast-moving atmospheric disturbance, a favorable ocean depth for resonance, and a coastline that amplifies the arriving oscillation.

Against this background, the comparison performed in the new study takes on practical significance. The authors compared the peak amplitudes of the pressure disturbances produced by the fronts they observed over the Moscow region with the peak pressure amplitudes of synoptic disturbances and atmospheric gravity waves that have been associated with meteorological tsunamis in the coastal zones of the ocean. From this comparison they estimated the amplitudes of the wave precursors of strong atmospheric fronts, and the pressure perturbations that these fronts can induce, in cases where the resulting disturbances would be capable of generating meteotsunamis along ocean and sea coasts. The logic is straightforward: if the pressure signatures of fronts observed far inland overlap with the pressure signatures known to drive destructive sea-level oscillations elsewhere, then the same class of atmospheric disturbance can serve as a common indicator of meteotsunami potential, regardless of where the front happens to be observed.

The study also connects to a broader and rapidly evolving research landscape. The 2022 eruption of the Hunga Tonga–Hunga Haʻapai volcano demonstrated dramatically that atmospheric pressure waves, including Lamb waves circling the globe, can trigger tsunami-like sea-level responses across entire ocean basins, and multiple studies cited in the paper analyzed that event. More recently, researchers have documented compound flood hazards in which the arrival of a volcanic tsunami coincided with a storm surge and a meteotsunami on the same coastline, a reminder that atmospheric and oceanic wave systems can converge on coastal communities simultaneously. Within this context, the identification of frontal wave precursors as potential indicators of dangerous pressure forcing adds a new layer to the forecasting problem, one that operates on the scale of individual weather systems rather than global wave trains.

The practical outcome of the research is a proposed monitoring method. The authors suggest simultaneously observing infrasound and atmospheric gravity waves in the period range preceding atmospheric storms, in order to assess the possibility that those storms will generate meteorological tsunamis in coastal areas. Infrasound, sound at frequencies below the range of human hearing, is generated by meteorological fronts and propagates efficiently through the atmosphere, while gravity waves register as coherent pressure oscillations at the surface. Observing both together, the authors argue, would allow forecasters to detect the atmospheric signature of an intensifying storm system early, estimate the strength of the pressure perturbations it is likely to deliver, and evaluate whether the conditions for meteotsunami generation, including resonance with coastal waters, might be met. Such a capability would complement existing meteotsunami research, which increasingly relies on nested regional atmospheric and ocean models to predict where and when destructive waves will form.

The work, supported by the Russian Science Foundation and conducted by researchers at the A.M. Obukhov Institute of Atmospheric Physics of the Russian Academy of Sciences, together with colleagues at Lomonosov Moscow State University, the Illichev Pacific Oceanological Institute and the Ishlinsky Institute for Problems in Mechanics, illustrates how decades of patient, ground-based measurement can illuminate a hazard that is usually studied only after it strikes. Long-term microbarograph records from a mid-continental network, far from any ocean, turn out to speak directly to a coastal danger, because the atmospheric waves that precede fronts obey the same physics everywhere. If the proposed dual monitoring of infrasound and gravity waves can be integrated into operational practice, coastal communities may one day receive warning not from the sea itself, but from the faint tremors of the atmosphere that announce a dangerous storm long before its pressure jump reaches the shore.

Subject of Research: Atmospheric gravity wave precursors of fronts as indicators of meteotsunami-generating pressure disturbances

Article Title: Atmospheric fronts and their wave precursors as possible sources of meteorological tsunamis

Article References: Kulichkov, S. N., Chunchuzov, I. P., Golikova, E. V., Popov, O. E., Dolgikh, G. I., Zakirov, M. N., & Bulatov, V. V. (2026). Atmospheric fronts and their wave precursors as possible sources of meteorological tsunamis. Natural Hazards, 122(21), Article 664. https://doi.org/10.1007/s11069-026-08448-4

Image Credits: AI Generated

DOI: 10.1007/s11069-026-08448-4

Keywords: meteorological tsunami, atmospheric fronts, gravity waves, infrasound, microbarographs, Proudman resonance, coastal hazards, atmospheric pressure, storm forecasting, internal gravity waves, ocean waves, natural hazards