Remote Monitoring of Subsurface Flow Conditions in Rivers

The primary research goal is to develop techniques to determine subsurface turbulence from remote measurements using infrared imaging of the skin layer. We aim to infer flow rate, turbulence intensity and subsurface-generated turbulent structures from surface temperature patterns. We will take advantage of the two complementary indicators of subsurface flow provided by IR imagery: the thermal structures measured directly and the surface velocity fields obtained through various image processing techniques. We will (1) analyze the variability and structures of the thermal boundary layer, (2) compute the surface flow field from the IR imagery and infer further surface turbulence characteristics, (3) determine to which extent the turbulence in the boundary layer is due to surface forcing by analysis of the air-sea flux data and (4) determine empirical relationships of subsurface flow characteristics and of turbulence derived from in situ sub-surface data to the observed turbulence in the IR imagery. We further aim to determine the limits of remotely inferring flow rates, subsurface turbulence and bed stress from IR imagery. We will investigate how different wind, tides and wave breaking conditions affect our ability to remotely measure subsurface flow characteristics.