ESTIMATING SUSPENDED-SEDIMENT CONCENTRATION IN THE SANTA BARBARA CHANNEL USING THE MODIS/ASTER AIRBORNE SIMULATOR

Light is a crucial component of biomass-formation and drives a number of essential biogeochemical processes within the ocean. The distribution and characteristics of suspended-particles in a water column influence light penetrability in the ocean and can become increasingly complex in the near-shore environment. Thus, there is value in the determination of suspended-sediment concentration and other suspended-particle characteristics in complex coastal waters. Gathering such data via in situ measurements is time-consuming, costly, and often incomplete due to the quantity of samples needed for a satisfactory data-network. Technological advances have made it possible to remotely-sense ocean color from aerial platforms and have driven the development of many sensor- and site-specific algorithms for estimating suspended-sediment concentration.

The goal of this research was to use MODIS/ASTER (MASTER) imagery collected during the 2010 Student Airborne Research Program’s (SARP) science flights, to estimate suspended-sediment concentration in the Santa Barbara Channel, California. Laboratory reflectance measurements of sediment-water mixtures were used to develop a library of reference spectra for comparison with the MASTER imagery. Spectral Angle Mapper classification was employed using endmembers from the library of reference spectra to suspended-sediment concentration calculated using algorithms developed from other remote imagers (MODIS Terra, SPOT, SeaWiFS, and Landsat). Suspended-sediment concentration ranged from 0-300mg/L within the Santa Barbara Channel on the day of data collection. Algorithms developed to estimate suspended-sediment concentration are sensor- and site-specific, and remain one of the important factors left to be considered in the convoluted study of suspended-sediment in complex coastal environments.