Long-wave Response of the Coastal Ocean to Hurricane Landfall
Alexander Yankovsky, Dept. of Earth & Ocean Sciences, University of South Carolina
9 Oct 2009
Direct observations of the storm surge induced by Hurricane Wilma’s landfall on the West Coast of Florida on October 24, 2005 revealed a formation of a wave pulse propagating alongshore as Wilma moved inland. The wave height exceeded 1.5 m in detided sea level data but its magnitude was obscured in direct surge measurements because it propagated during the stage of low tide. The duration of this wave pulse was ~6 hrs and the propagation speed was ~13 m/s. The wave pulse was followed by a train of much weaker oscillations during the next 24 hrs. The observed wave is identified as an edge wave of large spatial and temporal scales. A set of numerical experiments has been conducted to delineate a generation of edge waves with large spatial and temporal scales by a fast-moving storm system. A fast-moving storm system crossing the shelf at a right angle produces a nearly symmetrical response of two edge wave trains propagating both downstream and upstream. When the storm trajectory deviates from the normal approach, the edge wave response is not symmetric: most of the energy propagates in the direction of the alongshore component of the storm translation velocity.