THE INFLUENCE OF TERRESTRIAL DOM WILL BE VISIBLE TO FUTURE HYPERSPECTRAL SENSORS VIA CHARGE-TRANSFER INTERACTIONS WHILE A PORTION OF MICROBIALLY-PRODUCED CDOM WILL BE DIRECTLY VISIBLE. ALGORITHMS CAPABLE OF DECOMPOSING HYPERSPECTRAL REFLECTANCE INTO COMPONENT INHERENT OPTICAL PROPERTIES INCLUDING CDOM ABSORPTION ARE BECOMING MORE WIDELY AVAILABLE THROUGH NASA-FUNDED EFFORTS. THESE TOOLS ARE CAPABLE OF DELINEATING THE SPECTRAL SHAPE OF CDOM ABSORPTION INCLUDING IN OPTICALLY COMPLEX COASTAL WATERS. PAST WORK HAS CONSIDERED THE SENSITIVITY OF THE PACE OCEAN COLOR INSTRUMENT TO DETECT CHANGES IN THIS SPECTRAL SHAPE WITH EARLY RESULTS INDICATING PACE HAS THE REQUISITE SIGNAL-TO-NOISE RATIO TO CHARACTERIZE SUBTLE SHIFTS IN SPECTRAL SHAPE. HOWEVER A COMPLETE WORKFLOW FROM DECOMPOSITION OF HYPERSPECTRAL REFLECTANCE INTO SPECTRALLY-RESOLVED INHERENT OPTICAL PROPERTIES AND SUBSEQUENT CHARACTERIZATION OF CDOM CYCLING HAS NOT BEEN DEMONSTRATED. LAKE SUPERIOR IS AN IDEAL SYSTEM TO DEVELOP AND TEST OUR ABILITY TO OBSERVE CDOM VARIABILITY FROM HYPERSPECTRAL SPACE-BORNE INSTRUMENTS. THE OJIBWE NAME FOR THE LAKE GICHI-GAMI MEANS GREAT SEA AN APPROPRIATE DESCRIPTION OF LAKE SUPERIOR WHERE PHYSICAL FORCING AND BIOGEOCHEMICAL CYCLING OF CDOM IS AKIN TO THAT IN THE COASTAL OCEAN. CDOM IS THE DOMINANT OPTICAL CONSTITUENT IN LAKE SUPERIOR TYPICALLY AN ORDER OF MAGNITUDE GREATER THAN OTHER ABSORBING CONSTITUENTS. WITH A WATER RESIDENCE TIME OF 191 YEARS THE TIMESCALES FOR DOM CYCLING IN THE LAKE ARE RELEVANT FOR UNDERSTANDING THE GLOBAL OCEAN CDOM CYCLE. THUS LAKE SUPERIOR PROVIDES A MODEL SYSTEM TO ASSESS OUR ABILITY TO OBSERVE CDOM CYCLING OVER SPACE AND TIME. THE RESEARCH PROPOSED HERE WILL: 1) CHARACTERIZE CDOM VARIABILITY OPTICALLY AND CHEMICALLY IN LAKE SUPERIOR TRIBUTARIES AND THE LAKE PROPER. 2) MODEL THE IMPACT OF VARIABILITY IN TERRESTRIAL AND MICROBIAL CDOM ON HYPERSPECTRAL WATER-LEAVING REFLECTANCE USING EXPERIMENTAL INCUBATIONS AND HYDROLIGHT. 3) UTILIZE AND REFINE EXISTING ALGORITHMS TO CHARACTERIZE THE SPECTRAL SHAPE OF CDOM ABSORPTION FROM HYPERSPECTRAL REFLECTANCE AND DETERMINE OUR ABILITY TO CHARACTERIZE CDOM CYCLING FROM HYPERSPECTRAL REFLECTANCE DATA CONSIDERING ALGORITHM UNCERTAINTIES AND THE SIGNAL-TO-NOISE RATIO OF PACE.

Research Foundation Of The City University Of New York, New York NY

Investigators