Storm Surge Essay

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Storm surge Mohamed sherif Physical oceanography DR: Tarek M. EL-Geziry June 8,2013 Contents 1 Mechanics 2 Measuring surge 3 Records 4 SLOSH 5 Mitigation 6 References A storm surge is an offshore rise of water associated with a low pressure weather system, typically tropical cyclones and strong extratropical cyclones. Storm surges are caused primarily by high winds pushing on the ocean's surface. The wind causes the water to pile up higher than the ordinary sea level. Low pressure at the center of a weather system also has a small secondary effect, as can the bathymetry of the body of water. It is this combined effect of low pressure and persistent wind over a shallow water body which is the most common cause of storm surge flooding problems. The term "storm surge" in casual (non-scientific) use is storm tide; that is, it refers to the rise of water associated with the storm, plus tide, wave run-up, and freshwater flooding. "Tidal surge" is incorrect since there is no such thing. When referring to storm surge height, it is important to clarify the usage, as well as the reference point. The National Hurricane Center defines storm surge as water height above predicted astronomical tide level, and storm tide as water height above NGVD-29. Most casualties during a tropical cyclone occur during the storm surge. In areas where there is a significant difference between low tide and high tide, storm surges are particularly damaging when they occur at the time of a high tide. In these cases, this increases the difficulty of predicting the magnitude of a storm surge since it requires weather forecasts to be accurate to within a few hours. Storm surges can be produced by extratropical cyclones, such as the Night of the Big Wind of 1839 and the Storm of the Century (1993), but the most extreme storm surge events typically occur as a result of tropical
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