Physical characteristics and evolution of a long-lasting mesoscale cyclonic eddy in the Straits of Florida from multi-platform measurements

Abstract:

The Straits of Florida (SoF) is a subtropical region hosting the largest reef system in the continental United States and rich in strong eddy activity as revealed by field surveys and remote sensing measurements. Mesoscale cyclonic eddies along the Florida Keys reef tract are known to be highly productive with abundant nutrients, phytoplankton, and copepods. These eddies are also connected to the transport of biochemical substances (fish larvae, nutrients, and pollutants) from the deep ocean to the shallow coastal reef environments. Some eddies persist over time scales of about 100 days, influencing the physical environments and biological productivity throughout the SoF. In this study, we investigate the physical and biochemical properties, and the vertical structure of a mesoscale cyclonic eddy that persisted for around 4 months in the SoF based on satellite ocean color and altimetry measurements, together with Argo float data and high resolution HYCOM model simulations. We use the angular momentum eddy detection and tracking algorithm (AMEDA), a widely-used methodology to detect and track the mesoscale cyclonic eddy. We also use energy analysis to analyze the eddy’s evolution process. In order to learn about the reoccurrence of the long-lasting cyclonic eddies in the SoF, we verify the eddy patterns from historical altimetry records with MODIS/Aqua Chlorophyll imagery, then apply the AMEDA method to the validated altimetry data to detect, track, and finally determine the occurrence frequency of the long-lasting cyclonic eddies in the SoF.