Water clarity patterns in South Florida coastal waters and their linkages to synoptic-scale wind forcing

Abstract

Temporal variability in water clarity for South Florida’s marine ecosystems was examined through satellite-derived light attenuation (Kd coefficients, in the context of wind- and weather patterns. Reduced water clarity alongFlorida’s coasts is often the result of abrupt wind-resuspension events and other exogenous factors linked to frontalpassage, storms, and precipitation. Kd data between 1998 and 2013 were synthesized to form a normalized Kd index(KDI) and subsequently compared with Self-Organizing Map (SOM)-based wind field categorizations to reveal spatiotemporal patterns and their inter-relationships. Kd climatological maximums occur from October through Decemberalong southern sections of the West Florida Shelf (WFS) and from January through March along the Florida Straits.Spatial clusters of elevated Kd occur along 3 spatial domains: central WFS, southern WFS, and Florida Straits near theFlorida Reef Tract, where intra-seasonal variability is the highest, and clarity patterns are associated with transitionalwind patterns sequenced with cyclonic circulation. Temporal wind transitions from southerly to northerly, typically accompanying frontal passages, most often result in elevated Kd response. Results demonstrate the potential of usingsynoptic climatological analysis and satellite indices for tracking variability in water clarity and other indicators relatedto biological health.