Remote Sensing of Coastal Waters in the North Slope of Alaska

Recent warming has made the Arctic Ocean increasingly navigable and more open to maritime traffic. Understanding and monitoring the physical and ecological changes resulting from the warming is important for a number of reasons, including scientific research, natural resource management, and national security imperatives. Remote sensing is a necessary tool for developing the needed monitoring capabilities. A prerequisite for developing remote sensing tools is a quantitative understanding of the optical properties of constituents in water. The rapid thawing of permafrost has resulted in the release of previously frozen permafrost materials into inland waterways that transport these materials into the ocean. The optical properties of these newly released materials and their impact on the remote sensing signal are yet to be studied comprehensively. The U.S. Naval Research Laboratory (NRL) is undertaking a project to study the optical properties of constituents transported into coastal waters of the North Slope region of Alaska by the three main rivers in the region, namely, the Sagavanirktok, Kuparuk, and Colville rivers, with the goal of developing remote sensing algorithms specific to coastal Arctic waters for determining constituent concentrations and benthic characteristics, taking into account the mass-specific inherent optical properties of constituents in water. We present here results from analyzing Landsat-8 and Sentinel-2 data from the North Slope region for the last several years that reveal sediment patterns and flow dynamics associated with coastal waters.