Effects of extreme events on residual circulation for Tampa Bay, Florida

A numerical circulation model of Tampa Bay, Florida is used to simulate the flow field and tidal residual circulation for 2001-2004. This model is used to investigate the effects of extreme events on the residual circulation of the bay. The three extreme events that are used in this study are: Hurricane Frances, Hurricane Jeanne, and an extreme winter frontal passage that occurred on December 26, 2004. Each extreme event was divided into phases that were chosen by wind peaks and times of velocity inflow and outflow. There were three phases to the hydrodynamics effect of Frances on Tampa Bay. Hurricane Jeanne and the winter frontal passage each had two phases. An important difference between the three extreme events is the duration of each; Hurricane Frances lasted approximately two and a half days, Hurricane Jeanne affected the bay area for about twenty-four hours, and the extratropical storm passed within 16 hours. Winds were six standard deviations higher than the 2004 mean (4.06 m s-1) during Hurricane Frances, and seven standard deviations higher during both Hurricane Jeanne and the extratropical storm. Water levels reached four standard deviations during Hurricane Frances and the extratropical storm, and two standard deviations during Hurricane Jeanne. The difference between these results is due to the timing of each event with the tides, whether it was in or out of phase with the tides. During phase 2 of Hurricane Frances there was a total volume inflow of m3, for an increase of 60% in bay volume. There was a total volume outflow during phase 3 of m3, a 28% decrease. During Hurricane Jeanne there was a total volume inflow of m3 (30% increase) and total volume outflow of m3 (14% decrease). The extratropical storm showed a total volume inflow of m3 (29% increase) and a total volume outflow of m3 (31% decrease). Though the increase and decrease of volume for each event was different, they all had the same affect on the bay, causing changes in the residual circulation over time scales of these extreme events