Meteotsunami

The paper examines the possibility that tsunami event recorded in the western Black Sea on 7 May 2007 was triggered by a traveling atmospheric disturbance. As meteotsunamis are favored by specific synoptic conditions, we inspected available ground and sounding observations, European Centre for Medium‐Range Weather Forecasts reanalysis fields, and satellite‐based products and compared them to the documented Mediterranean meteotsunamis. We found an atmospheric disturbance traveling toward 30° (NNE) with amplitude of 2–3 hPa and propagation speed of about 16 m/s, passing through few tens of kilometers wide pathway over the region affected by the tsunami. This disturbance occurred in the lower troposphere, but it was capped by instable convective cell that preserved gravity disturbance's coherence over a region at least 150 km long. An ocean modeling study showed that such a disturbance is capable of generating large tsunami waves and strong currents over the shallow regions, follow...

On 27 May 2012, atmospheric conditions gave rise to two convective systems that generated a series of waves in the meteotsunami band on Lake Erie. The resulting waves swept three swimmers a 0.5 mi offshore, inundated a marina, and may have led to a capsized boat along the southern shoreline. Analysis of radial velocities from a nearby radar tower in combination with coastal meteorological observation indicates that the convective systems produced a series of outflow bands that were the likely atmospheric cause of the meteotsunami. In order to explain the processes that led to meteotsunami generation, we model the hydrodynamic response to three meteorological forcing scenarios: (i) the reconstructed atmospheric disturbance from radar analysis, (ii) simulated conditions from a high‐resolution weather model, and (iii) interpolated meteorological conditions from the NOAA Great Lakes Coastal Forecasting System. The results reveal that the convective systems generated a series of waves in...

On 27 May 2012, atmospheric conditions gave rise to two convective systems that generated a series of waves in the meteotsunami band on Lake Erie. The resulting waves swept three swimmers a 0.5 mi offshore, inundated a marina, and may have led to a capsized boat along the southern shoreline. Analysis of radial velocities from a nearby radar tower in combination with coastal meteorological observation indicates that the convective systems produced a series of outflow bands that were the likely atmospheric cause of the meteotsunami. In order to explain the processes that led to meteotsunami generation, we model the hydrodynamic response to three meteorological forcing scenarios: (i) the reconstructed atmospheric disturbance from radar analysis, (ii) simulated conditions from a high‐resolution weather model, and (iii) interpolated meteorological conditions from the NOAA Great Lakes Coastal Forecasting System. The results reveal that the convective systems generated a series of waves in...

La madrugada del dia 19 de agosto de 2014 ocurrio, en el puerto de Ciutadella de Menorca, una rissaga, u oscilacion marina de notable amplitud, cercana al metro y medio, que provoco inundacion parcial de muelles y terrazas. El fenomeno habia sido previsto por el servicio de prediccion de rissagues de AEMET (encuadrado en el Plan Nacional de Avisos de Fenomenos Meteorologicos Adversos), pero con poca anticipacion y en grado insuficiente. El aviso era amarillo y a oscilaciones de mas de un metro de amplitud les corresponde aviso naranja. La amplitud de esa rissaga fue considerada sorprendente, en vista a la situacion meteorologica presente. En este trabajo, despues de una revision sobre las rissagues en general, analizamos algunos detalles de la rissaga de 19 de agosto y del ambiente meteorologico en que se desarrollo y concluimos que la amplitud de esa rissaga es explicable, no sin quedar algunos puntos oscuros, pero poco o nada previsible.

The meteotsunami early warning system prototype using stochastic surrogate approach and running operationally in the eastern Adriatic Sea is presented. First, the atmospheric internal gravity waves (IGWs) driving the meteotsunamis are either forecasted with state‐of‐the‐art deterministic models at least a day in advance or detected through measurements at least 2 hr before the meteotsunami reaches sensitive locations. The extreme sea‐level hazard forecast at endangered locations is then derived with an innovative stochastic surrogate model—implemented with generalized polynomial chaos expansion (gPCE) method and synthetic IGWs forcing a barotropic ocean model—used with the input parameters extracted from deterministic model results and/or measurements. The evaluation of the system, both against five historical events and for all the detected potential meteotsunamis since late 2018 when the early warning system prototype became operational, reveals that the meteotsunami hazard is con...

Meteotsunamis pose a unique threat to coastal communities and often lead to damage of coastal infrastructure, deluge of nearby property, and loss of life and injury. The Great Lakes are a known hot-spot of meteotsunami activity and serve as an important region for investigation of essential hydrodynamic processes and model forecast requirements in meteotsunami-induced coastal flooding. For this work, we developed an advanced hydrodynamic model and evaluate key model attributes and dynamic processes, including: (1) coastal model grid resolution and wetting and drying process in low-lying zones, (2) coastal infrastructure, including breakwaters and associated submerging and overtopping processes, (3) annual/seasonal (ambient) water level change, and (4) wind wave-current coupling. Numerical experiments are designed to evaluate the importance of these attributes to meteotsunami modeling, including a “representative storm” scenario in the context of regional climate change in which a me...

En ambientes acuáticos estratificados poco profundos, las márgenes y la batimetría imponen condiciones de contorno que posibilitan la generación de ondas estacionarias que, a diferencia de aquellas que pueden desarrollarse en mar abierto, sólo admiten ciertas frecuencias. En este trabajo se presenta una metodología de procesamiento de datos que permite reconocer ondas internas de baja intensidad, generadas en tales sistemas por el forzamiento de la circulación, debido a las mareas o los vientos. La misma se basa en el análisis de las series temporales de velocidad construidas a partir de los registros de un perfilador acústico Doppler ubicado en una posición fija en el estuario del río de La Plata. El análisis de las componentes principales y las transformaciones de Fourier y wavelet se emplearon para extraer información sobre la variabilidad de la circulación estuarina y la estructura vertical de las corrientes en diferentes escalas temporales. Los resultados muestran comportamient...

Two hazardous typhoons, Lionrock (August 2016) and Jebi (September 2018), destructively affected the coast of Japan and produced extreme sea level variations. The results of field surveys in the impacted regions showed that multiple deaths and extensive floods were caused by the combined effect of low-frequency sea level raise (storm surges) and intensive high-frequency (HF) tsunami-like waves (meteotsunamis). The data from ten tide gauges for the 2016 event and eight gauges for the 2018 event were used to examine the properties of the observed sea levels, to estimate the relative contribution of the two sea level components and to evaluate their statistical characteristics (maximum wave heights, amplitudes and periods of individual components, etc.). For the 2016 event, we found that the surge heights were from 12 to 35 cm and that the mean contribution of surges into the total observed sea level heights was ~ 39%; the meteotsunami amplitudes were from 22 to 92 cm, and they contrib...

The paper examines the possibility that tsunami event recorded in the western Black Sea on 7 May 2007 was triggered by a traveling atmospheric disturbance. As meteotsunamis are favored by specific synoptic conditions, we inspected available ground and sounding observations, European Centre for Medium-Range Weather Forecasts reanalysis fields, and satellite-based products and compared them to the documented Mediterranean meteotsunamis. We

In addition to the tsunami hazard posed by distant great earthquakes, Rapa Nui (Easter Island), in the Southeast Pacific Ocean, is exposed to frequent and intense coastal storms. Here, we use sea-level records and field surveys guided by video and photographic footage to show that extreme sea levels at Rapa Nui occur much more frequent than previously thought and thus constitute an unrecognized hazard to the inland’s maritime supply chain. We found that extreme sea-level events, including the two most extreme (March 5th and May 5th, 2020) in our 17-month-long analyzed period (from January 1st, 2019, to May 31st, 2020), resulted from constructive superpositions of seiches on the shelf, storm surges and high tides. By further analyzing time series of atmospheric and wind-generated wave data, we conclude that these extreme sea levels are ultimately driven by the breaking of large waves near the coastline (i.e., wave setup), with lesser contribution of barometric setup and even less of ...

Se realizo un analisis de la onda de marea en la bahia de Santa Marta. La onda de marea fue medida mediante la ayuda de un mareografo WLR 7 de la familia Aandera. A partir de las series de tiempo obtenidas se determino la amplitud y la fase de los constituyentes principales de la marea mediante un analisis de armonicos efectuado con la tecnica de ajuste de minimos cuadrados. Se encontro una marea con caracteristicas mixta principalmente diurna conformada por 12 constituyentes, de ellos seis son de caracter diurno (K1, O1, P1, Q1, J1, OO1) y cinco de caracter semidiurno (M2, S2, K2, N2, Mu2) ademas de la Componente lunisolar sinodica quincenal (Msf).

Es una palabra de origen japonés formada por dos términos : tsu, que significa "puerto" o "bahía",y nami "ola"; e indica un maremoto en un puerto. En general, el término tsunami se aplica a una ola gigante, de más de 15 metros de altura con períodos en el rango de 5 a 60 minutos, que llega a la costa y produce grandes inundaciones.