Local and non-local response of the Straits of Florida to tropical cyclones during 1999-2005

Several hurricanes passed through or near the NSU/USF mooring array during seven hurricane seasons. The mooring array is deployed on the shelf off Broward County, Southeast Florida. It contains acoustic Doppler current profiler (ADCP), temperature and temperature/ salinity sensors, a wave and water level gauge. Data from the bottom mooring at 11 m isobath have been collected almost continuously since July 1999. Our present observational statistics includes response to hurricanes Floyd and Irene in 1999, Frances and Jeanne in 2004, and Katrina in 2005 (data on Hurricane Rita, Hurricane Wilma, and approaching Tropical Storm Gamma have not yet been retrieved on the moment of the abstract submission). Sea level deviations observed during the passage of 1999-2005 hurricanes through the Straits of Florida were relatively small. Local response of the current velocities to the passage of hurricanes was prominent with considerable increase of both along- and cross-shelf components. This increase, however, did not significantly exceed maximum current velocity fluctuations during non-hurricane conditions associated with energetic internal tides or submescale eddies in the Florida Current. Sediment concentrations inferred from the ADCP echo intensity signal show dramatic increase of sediment load during hurricanes Irene and Katrina, which presumably is related to intense wind waves developed in the Straits of Florida during those two hurricanes. Nonlocal response of the Straits of Florida to hurricanes will be discussed in the context of the western boundary current system including the Loop Current, Florida Current, and Gulf Stream. Impacts to local eco-systems including potential impact on coral reefs and beach re-nourishment efforts will be discussed in context of a possible trend to increased hurricane activity with anticipated governmental responses thereto.