You are here:
Optical Models for Remote Sensing of Colored Dissolved Organic Matter Absorption and Salinity in New England, Middle Atlantic and Gulf Coast Estuaries USA
Citation:
Keith, D., R. Lunetta, AND B. Schaeffer. Optical Models for Remote Sensing of Colored Dissolved Organic Matter Absorption and Salinity in New England, Middle Atlantic and Gulf Coast Estuaries USA. Remote Sensing. MDPI, Basel, Switzerland, 8(4):283, (2016).
Impact/Purpose:
Colored dissolved organic matter (CDOM), also known as yellow substance or gelbstoff, is an important water color parameter for the study of lacustrine, near-coastal, and estuarine biological processes. Along with chlorophyll a, the absorption of light by CDOM is important to the structure and function freshwater and saltwater ecosystems. CDOM absorption can also indicate the input and distribution of terrestrial organic matter and is a key factor in the broad understanding of biogeochemical processes in freshwater and saltwater environments. Salinity is a key factor when monitoring water quality variables (e.g., dissolved oxygen concentration). Salinity variations also strongly influence biogeochemical processes as well as create biological and chemical gradients both horizontally and vertically within the water column. Published studies have derived CDOM absorption estimates and salinity values from satellite spectral band ratios using regionally models that use locally derived coefficients. This study demonstrated that a bio-optical model that uses a single set of coefficients can be derived from remote sensing data which accurately estimates the range of CDOM absorptions found in estuarine, inland, and coastal environments. Further, a general salinity was created, based the CDOM bio-optical model, to estimate salinities from oligohaline to polyhaline waters of the United States from New England to the Gulf of Mexico.
Description:
In estuarine and nearshore ecosystems, salinity levels, along with temperature, control water column stratification, the types and locations of plants and animals, and the flocculation of particles. Salinity is also a key factor when monitoring water quality variables (e.g., dissolved oxygen concentration). Ocean color algorithms have been successfully developed to estimate chlorophyll a and total suspended solids concentrations in coastal and estuarine waters but few have been created to estimate CDOM absorption and salinity from the spectral signatures of these waters. The goal of this activity was to use multispectral and hyperspectral signatures retrieved from the Medium Resolution Imaging Spectrometer (MERIS) and the International Space Station (ISS) Hyperspectral Imager for the Coastal Ocean (HICO) to estimate the surface salinities of rivers, coastal bays, and estuaries along the US East and Gulf coasts using reflectance band ratios in the red and blue-green and light absorption by colored dissolved inorganic matter (CDOM). Salinities predicted by the algorithm were successfully validated over a range of oligohaline (< 5 psu) to polyhaline (> 20 psu) environments and CDOM absorption magnitudes from 0.1 to 7.0 m-1 in waters from Narragansett Bay (Rhode Island); the Neuse River Estuary (North Carolina); Pensacola Bay (Florida); Choctawhatchee Bay (Florida); St. Andrews Bay (Florida); St. Joseph Bay (Florida); and inner continental shelf waters of the Gulf of Mexico.
