Estimating absorption due to detritus and colored dissolved organic material from satellite and potential applicability as tracer for the Mississippi river plume

The turbid, nutrient and sediment rich Mississippi River plume impacts many biological, chemical, and physical processes in the Gulf of Mexico. An ability to demarcate and track the river plume, or to quantify the influence Mississippi River plume and use it as a model input, will enhance our understanding of the plume´s link to hypoxia, coastal currents, and harmful algal blooms, among others. The plume and coastal water may be separated by their salinity, which loosely co-varies with the amount of colored dissolved organic material (CDOM), and detritus in the water. In this study, we developed an algorithm to remotely estimate the amount of light absorbed by CDOM and detritus using the Sea-Viewing Wide Field-of-view Sensor (SeaWiFS). The derived absorption fields were compared to a time series of surface salinity at Grand Terre, Louisiana, between October 1998 and December 1999; and also to salinity fields sampled near the mouth of the Mississippi in the summers of 1999, 2000, 2001, 2002, and 2003