WATER CLARITY HAS LONG BEEN CONSIDERED A SENTINEL RESPONSE VARIABLE TO ENVIRONMENTAL CHANGE DUE TO ITS COMPLEX INTERACTIONS WITH PHYSIO-CHEMICAL FRESHWATER PROCESSES. IN LAKES AND RESERVOIRS WATER CLARITY PROVIDES A ROBUST METRIC OF ECOSYSTEM HEALTH BY INTEGRATING SURROUNDING TERRESTRIAL AND ATMOSPHERIC CHANGES. IMPAIRED WATER CLARITY DECREASES EPILIMNION DEPTH AND RESTRICTS LIGHT AVAILABILITY FOR PHOTOSYNTHESIS BY SUBMERGED MACROPHYTES AND OTHER PRIMARY PRODUCERS. THIS ALTERATION OF LACUSTRINE SYSTEMS CAN SIGNIFICANTLY REDUCE BIODIVERSITY AND LAKE METABOLISM WITH STRONG IMPLICATIONS FOR INLAND WATER CARBON CYCLING. WHILE THE DRIVERS OF WATER CLARITY FUNCTION AT REGIONAL AND CONTINENTAL SCALES TRADITIONAL METHODS OF IN SITU MEASUREMENT ARE SPATIALLY AND TEMPORALLY RESTRICTED TO LOCAL ENVIRONMENTS. RECENT ADVANCES IN REMOTE SENSING TECHNOLOGIES AND PRODUCTS ARE INCREASING THE FEASIBILITY OF CONDUCTING SUCH MEASUREMENTS OVER LARGE SPATIAL AND TEMPORAL DOMAINS. THE NATIONAL WATER QUALITY PORTAL (WQP) AND THE LAKE MULTI-SCALED GEOSPATIAL AND TEMPORAL DATABASE (LAGOS-NE) ARE TWO RECENT DATABASES THAT HAVE COMPILED AND STANDARDIZED WATER QUALITY FIELD MEASUREMENTS FROM THOUSANDS OF GOVERNMENTAL ACADEMIC AND NON-PROFIT INSTITUTIONS. IN TOTAL THE TWO DATABASES HAVE ASSIMILATED MORE THAN 3.6 MILLION HISTORIC WATER CLARITY MEASUREMENTS DISTRIBUTED ACROSS 62 000 UNIQUE SITES. A DATASET OF THIS SIZE AND SPATIAL COVERAGE CREATES NEW OPPORTUNITIES FOR REMOTE SENSING MODEL DEVELOPMENT AND VALIDATION. USING GOOGLE EARTH ENGINE WE PROPOSE TO INTEGRATE THIS DATASET WITH THE LANDSAT TM ETM+ AND OLI COLLECTIONS RESULTING IN ~263 000 IN SITU WATER CLARITY MEASUREMENTS TEMPORALLY COINCIDENT WITH A CLOUD-FREE LANDSAT OVERPASS. WE WILL TO USE THIS DATA TO DEVELOP GENERALIZABLE REMOTE SENSING WATER CLARITY MODELS ACROSS OPTICALLY DIVERSE WATERBODIES AT A NATIONAL SCALE

University Of North Carolina At Chapel Hill, Chapel Hill NC

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