10:45–11:00 | ABSTRACT 1362
HYPERSPECTRAL MONITORING OF DOC BIOGEOCHEMISTRY ACROSS ESTUARINE TO SHELF WATERS
Dissolved organic matter (DOM) plays an essential role in carbon cycling and water quality across inland, estuarine, and coastal waters. DOM in the coastal ocean is extremely dynamic, often varying across steep spatial gradients and short timescales, and experiencing intense biogeochemical and physical processing. Current and planned hyperspectral satellite imagers offer opportunities to quantify inland-to-coastal DOM processes by separating in-water constituents in optically complex waters and characterizing spectral signatures associated with biogeochemical and physical properties. To utilize these capabilities, we developed hyperspectral, regionally transferable algorithms to improve retrievals of dissolved organic carbon (DOC) concentration and retrieve indicators of colored DOM (CDOM) composition across a wide range of optical water types and environmental conditions. Algorithms were developed using an in-situ dataset of simultaneous hyperspectral radiometry, UV-visible CDOM absorption, DOC, and ancillary parameters (other IOPs, chlorophyll-a, DOM fluorescence) compiled from research cruises on the Atlantic, Pacific, Gulf, and Arctic coasts of the United States. Empirical and machine learning approaches utilizing hyperspectral information outperformed existing multispectral approaches for retrieving coastal DOC and allowed for the retrieval of CDOM spectral shape as an indicator of DOM composition, sourcing, and degradation. Algorithms were applied to existing spaceborne hyperspectral imagers (e.g. NASA PACE and EMIT) to quantify DOC and CDOM composition across shelf waters, urban seas, and inland waters. Application to spaceborne sensors also helped evaluate the impact of atmospheric correction uncertainties, particularly in the UV–blue range, on DOM retrieval in turbid to clear coastal settings.
Joshua Harringmeyer, The City College of New York, [email protected], https://orcid.org/0000-0001-8108-0644
Maria Tzortziou, The City College of New York, [email protected], https://orcid.org/0000-0002-4510-7827
