On the afternoon of April 13, 2018, a large wave rushed across Lake Michigan, flooding the shores of beautiful beach towns in Ludington, Michigan, damaging home and boat docks and flooding intake pipes. Thanks to local citizen photos and other data, NOAA scientists reconstructed the event with a model and determined that this was the first recorded meteotsunami on the Great Lakes caused by atmospheric inertial gravitational waves. Did.
Atmospheric inertial gravitational waves are waves of air that are 6 to 60 miles in length and are generated when a stable mass of air is replaced by air masses with significantly different pressures. This synchronizes the movement of the water on the surface of the lake in harmony with the two singers, which can move air waves with rising and falling pressures, affecting the water below.
“The meteotsunami was amazing,” said Debbie Magrotin of Rudington, who took a picture of the event. “The water between the breakwaters did not go down as much as the water outside the breakwaters, creating a waterfall that ran down over the breakwaters. If this event occurs in the summer, flush people off the breakwaters immediately. I think I was able to do it. “
Meteotsunamis resulting from this type of atmospheric conditions are common throughout the world, but in the Five Great Lakes, well documented, caused by sudden heavy thunderstorms in which both wind and pressure changes play important roles. There are almost no meteotsunamis.
Combination of water model and meteorological model
Currently, there are no predictive models in the United States that effectively predict meteotsunamis, but new NOAA studies based on Rudington waves are based on existing NOAA numerical and hydrodynamic forecast models that scientists can use to predict these meteotsunamis. It shows that it is possible to predict the atmospheric waves that drive the vehicle in minutes to hours. Advance.The study is published in a special edition of the journal Natural disasters About meteotsunami.
“The good news about this type of meteotsunami is that it’s easier to predict than a meteotsunami caused by a thunderstorm,” said Eric Anderson, a marine scientist and lead author of the study at NOAA’s Five Great Lakes Environmental Institute. .. “Our short-range meteorological model can pick up these atmospheric waves, but it is more difficult to predict thunderstorms.”
Meteotsunami is a lesser-known category of tsunami. Unlike better-known tsunamis such as Indonesia’s catastrophic 2004 Boxing Day tsunami caused by submarine earthquakes, meteotsunamis are caused by a combination of weather, especially changes in barometric pressure, strong winds, and thunderstorm activity. ..
“Because the lakes are relatively small, meteotsunamis usually require more than a barometric jump to move them,” Anderson said. “Thunderstorms and winds come there and give them a push.”
The Great Lakes have a history of meteotsunamis
Meteotsunamis occur around the world and are known to occur primarily along the Great Lakes and the east coast and coast of the Gulf of Mexico in the United States. The Great Lakes meteotsunami is particularly insidious as it bounces off the coastline and can come back again when the sky clears. They are relatively rare, usually small, and the largest produce waves of 3 to 6 feet, which occur only about once every 10 years.
Predicting these waves in advance gives communities warnings that could save lives and allows residents and businesses to take steps to better protect their property. The Ludington Meteotsunami caused property damage but was not seriously injured. If a meteotsunami struck in the summer when swimmers, anglers and vacationers flock to the beaches, parks and oceans of the shore, it would be different, as was the case with the meteotsunami that killed eight people in Chicago in June 1954. It may have been a story. ..
“That’s the gap in our predictions,” Anderson said. “This and other studies are making it possible for us to predict them in advance.”
Pilot project to warn of potentially dangerous “meteotsunami” waves on the Great Lakes
Eric J. Anderson et al, High Amplitude Atmospheric Inertia at Lake Michigan-Gravity Wave Meteotsunami, Natural disasters (2020). DOI: 10.1007 / s11069-020-04195-2
Provided by NOAA Headquarters
Quote: According to the survey, the forecast of the meteotsunami (April 1, 2021) obtained on April 1, 2021 is shown from https: //phys.org/news/2021-04-meteotsunamis.html. I am.
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Studies show the prospect of predicting meteotsunami
Source link Studies show the prospect of predicting meteotsunami