ONR Satellie Imagery Research Team 2003-2004

"Remote Sensing of Turbidity and Water Clarity in the Atlantic Ocean with the
use of SeaWiFS Data"

Turbidity can be defined as the cloudiness of water, caused by suspended materials. The greater the amount of total suspended solids in the water, the higher the measured turbidity. Causes of turbidity include soil erosion, waste discharge, urban runoff, and algal growth.

Highly turbid ocean waters are those with a large number of scattering particulates in them. In both highly absorbing and highly scattering waters, visibility into the water is reduced. The highly turbid water still reflects light while the highly absorbing water is very dark. The scattering particles that cause the water to be turbid can be composed of many things, including sediments and phytoplankton.
The fishing industry is dependent upon knowledge of small variations in water temperature and visibility. In addition, high levels of turbidity over long periods of time can greatly diminish the health and productivity of the estuarine ecosystem. Turbid waters decrease light penetration into the water, thereby reducing the area available for submerged aquatic plants to grow. As turbidity increases, water loses its ability to support diverse aquatic organisms. Turbidity also warms water by absorbing heat, blocks photosynthesis, irritates and clogs gills of fish, and decreases visibility for predators and prey.

The frequency and extent of turbidity events in the Atlantic Coast was studied. SeaWiFS Ocean Color data was utilized to generate secchi disk depth estimates. Those estimates were then used to study water clarity and for analysis of turbidity events. TeraVision was used for processing and analyzing data. SeaWiFS datasets were provided by the Center of Excellence in Remote Sensing Research and Education (CERSER), located on the campus of Elizabeth City State University.