11:00–11:15 | ABSTRACT 1344
HIGH RESOLUTION AIRBORNE AND SATELLITE REMOTE SENSING OBSERVATIONS OF COASTAL DISSOLVED ORGANIC CARBON DYNAMICS ALONG THE NORTH SLOPE OF ALASKA
The influx and transformation of terrestrial dissolved organic matter (DOM), nutrients, and sediments transported by Arctic rivers significantly shape regional and coastal ecology, biogeochemical cycles, and ecosystem resilience. High-resolution remote sensing from airborne and satellite platforms provides an unparalleled capability to capture these biogeochemical gradients at multiple scales across the Arctic land-ocean continuum. We applied a robust multispectral remote-sensing algorithm approach, optimized for Alaska’s North Slope, to both satellite (Sentinel-2/MSI, Sentinel-3/OLCI) and airborne (AVIRIS-NG) imagery, to provide a first-of-its kind view of the complex DOM spatiotemporal dynamics that characterize this Arctic coastline. Algorithms included retrievals of colored dissolved organic matter (CDOM) absorption at 300 nm, absorption spectral slope (S275–295), and dissolved organic carbon (DOC) concentrations. Several atmospheric correction approaches were evaluated to minimize retrieval errors. Remotely sensed DOC showed excellent agreement with summer field observations across spatial and temporal scales. Both airborne and satellite imagery revealed intense gradients in DOM amount and quality across the Arctic river-to-ocean continuum, strong accumulation within the North Slope’s barrier islands, and transition to less humic, progressively degraded, and/or biologically derived DOM further offshore. Remote sensing retrievals captured the seasonal variability in DOM and its linkage to the spring freshet and shifting riverine hydrology. Capturing these interactions from airborne and space-based platforms is essential for monitoring shifting biogeochemical cycles and environmental processes along this remote and challenging to access coastline, especially as accelerated warming continues to transform the Arctic Ocean and as economic and geopolitical interests in the region continue to grow.
Maria Tzortziou, CCNY/NYC, GSFC/NASA, [email protected], https://orcid.org/0000-0002-4510-7827
Jonathan Sherman, NOAA CoastWatch at NOAA Southwest Fisheries Science Center, [email protected]
