Tidal and non-tidal characteristics of water levels and flow in the Apalachicola Bay, Florida

M. Koch^a, H. Sun^b

^aDepartment of Geohydraulics and Engineering Hydrology, University of Kassel, Kurt-Wolters Straße 3, 34109 Kassel, Germany

^bDepartment of Geological Sciences, Riders University, Lawrenceville, NJ 08648, USA

Email: Kochm@hrz.uni-kassel.de

Abstract

Apalachicola Bay is one of the most productive estuaries in Florida. Tidal forces influence water levels, current velocities and salinity mixing in the estuary. These parameters in return affect the aquatic habitats and their productivity. The tidal wave enters the bay in the east and exits it through several barrier island cuts in the west. Accordingly, the tidal amplitudes are higher in the eastern than in the western section of the estuary. The bay shows a mixed tidal type, mainly semi-diurnal in the eastern and central sections, but diurnal in the western part of the bay. The rotary tidal currents show complicated elliptical flow paths. Fluctuations of the tidal water levels result in short-term periodical variations of salinity and are responsible for the mixing of fresh river water and saline ocean water. Long-term mean currents influenced by the non-tidal shelf currents from the Gulf and density gradients created by fresh river water and oceanic saline water are responsible for the net current flow of the estuary.