ARCUS 17th Annual Meeting and Arctic Forum 2005

Analyzing North Slope River Plume Suspended Sediment with MODIS Reflectance Data

Anne Hickey¹, James Maslanik^2
1Environmental Studies, University of Colorado, 311 UCB, Boulder, CO, 80309, USA, anne.hickey@colorado.edu
²CCAR, University of Colorado, 431 UCB, Boulder, CO, 80309, USA, james.maslanik@colorado.edu

Rivers function to integrate terrestrial processes and climatic conditions occurring in a watershed and deliver the product of these processes and conditions to the ocean. As a result, changes in the terrestrial system may be observed in nearshore river plumes. Two vectors of environmental change currently affecting the terrestrial system on the North Slope of Alaska are warming temperatures and oil and gas development, both of which alter the tundra’s thermal regime and lead to increased erosion. The advent of recent Earth Observing satellites providing daily coverage in the Arctic and the development of methods to extract suspended sediment information from visible and near-infrared (NIR) satellite reflectance data provide the ability to develop a cost-effective program to monitor suspended sediment from North Slope Rivers remotely, providing information about changes in terrestrial processes. In developing such a program, it is first necessary to know the degree to which “external” factors such as wind-induced entrainment of offshore sediments might be contributing to the satellite-observed river plume reflectances. Preliminary results comparing MODIS NIR reflectance data from Alaskan North Slope river plumes with wind and river discharge data indicate that wind resuspension of nearshore sediment significantly contributes to the NIR signal from the Sagavanirktok River plume, contributes to the Kuparuk River plume primarily at higher wind speeds, and appears to have a negligible effect on signals from the Colville River plume.