Variability of the Reflectiance and Transparency of River Plume Waters Caused by Hydrodynamic Proecesses

摘要

The goal of this paper is to present in situ data on the reflectance and transparency of river plumes and to interpeet the observed variability in terms of hydrodyanic processes. Data has been obtained for river plumes in the Black Sea and in Arctic ocean regions. Spectral reflectance was measured in the 400-700nm hand by a ship/helicopter-mounted spectradiometer and were supplemented by shipboard measurements of vertical profiles of the light attenuation coefficient. Remotely-sensed data shows the transition from freshwater to seawater with both sharp boudnary fronts and wide mixing zones. Internal fronts with quasi-periodic satial variability of reflectance were lso observed withinthe reiver plume. The observations are related ot the relevant hydrodyanic processes (fronts, advection and settling of particulate matter, internal waves). A radiance model was developed to match the vertical profile of optical proeprties to the observed variation of remotely-sensed reflectance.