The Effect of Wave Setup on Water Levels During Hurricane Irene
Erin E. Hopson: Center for Maritime Systems, Stevens Institute of Technology
Castle Point on Hudson, Hoboken, NJ 07030. (609) 661-0763
E-mail: ehopson@stevens.edu
Abstract:
Hurricanes, tropical storms, and nor’easters that contain heavy winds are often accompanied by water levels that greatly exceed their predicted values. Heavy winds blowing over large areas push the water up against the shoreline, increasing the mean water level and creating a storm surge. These storm surges greatly increase flooding and pose many hazards to coastal communities.
Hurricane Irene was the first storm of the 2011 Atlantic Hurricane season. It made landfall in New Jersey on August 28 as a Category 1 storm. At its peak, Irene was a Category 3 storm while it passed over the Bahamas. During Hurricane Irene, water levels observed in Atlantic City greatly surpassed the water levels recorded by the tide gauge located at the end of the Steel Pier. This talk will aim to explain the discrepancy in water levels through the phenomenon known as wave setup and re-calculate historic water levels.
Wave setup has been recognized as a significant contributor to storm surge. Research shows that wave setup can increase storm surge by up to 30%. A general rule of thumb is that wave setdown is 5% of maximum wave height and wave setup is 24% of maximum wave height. This means there is a sizable range of possible water levels, especially if the gauge is located at the point of maximum setdown. Currently, water levels are determined from gauge readings alone. The consideration of wave setup could have significant impacts on both historic water level records and many other tide gauges that are located on piers.
References:
Kline, S., 2009. Introduction of Wave Set-up Effects and Mass Flux to a Numerical Storm Surge Model. University of Florida, 10.
Biography:
Erin Hopson is a Masters student at Stevens Institute of Technology in Hoboken, New Jersey. She received her Bachelor of Engineering degree in Civil Engineering from Stevens in May of 2013. Erin is currently a graduate research assistant in the Coastal Engineering group in the Davidson Laboratory at Stevens. She is also the secretary of Stevens' student chapter of ASBPA.
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