A field study will be conducted in a partially mixed estuary, the Hudson River, with the objectives of quantifying and characterizing turbulent transport of momentum and salt, and relating these processes to the local and estuary-wide dynamical balances. The measurement program will use a combination boundary layer turbulence sensors, a microstructure profiler, moorings as well as a shipboard surveys to provide the velocity and salinity gradient data needed to resolve the baroclinic and advective contributions to the balances. The study should provide important new insights into the mechanisms of stratified turbulent boundary layers as well as estuarine dynamics.