Investigation of Coastal CDOM Distributions Using In-Situ and Remote Sensing Observations and a Predictive CDOM Fate and Transport Model

Abstract

Abstract : Our long-term goal is to interprete chromophoric dissolved organic matter (CDOM) sources, distributions, and dynamics in and around the NY/NJ Harbor Estuary, with a focus on significant freshwater events, through the creation of a robust, deterministic, high-resolution, four-dimensional, predictive model of CDOM fate and transport, validated against in-situ and remote sensing observations. An existing four-dimensional hydrodynamic and CDOM source tracking model was significantly updated and compared against a) concurrent datasets of in situ (EcoShuttle) CDOM observations available for the New York/New Jersey Harbor and, b) satellite-derived (SeaWiFS) surface CDOM distributions for the Harbor and its New York Bight Approaches (Bight Apex). The New York Harbor Observation and Prediction System (NYHOPS), a hydrodynamic/CDOM forecasting model incorporating CDOM fluorescence source strengths and first-order decay through photodegradation, was updated to a new high-resolution version shown to better capture the relevant hydrodynamic scales and associated CDOM sources and transport. The NYHOPS CDOM fate module was singificantly changed to include a more robust and deterministic bio-kinetic formulation of CDOM absorption loss due to photobleaching. Existing high-resolution local observations of CDOM fluorescence, absorption and other related variables, were used to locally calibrate the NYHOPS bio-kinetic module. CDOM distributions based on NYHOPS were compared to both the in-situ observations and SeaWiFS-derived spatial distributions, to continue interpretation of the CDOM data and facilitate an understanding of the processes that control CDOM distributions in estuarine and coastal waters.