River flow provides the buoyancy that supports plume stratification. Tides have a mixed effect, providing more buoyant outflow and stronger advection of low density water, but also more vertical turbulent mixing. Negative of the windstress is plotted, because of the destruction of stratification by wind-induced mixing. Its temporal structure has little influence on the frequency structure of the stratification, because near-surface fluctuations are much greater. The cross-shore flow is mostly offshore and typically weaker than the alongshore flow.
Velocities are much weaker than near the estuary mouth.
Above, amplitude scaleogram for alongshore windstress, below for stratification at N5. There are also sporadic, strong incursions of windstress into the tidal band, and a definite continuity of process between the tidal and subtidal bands in the stratification record. Because of rapidly fluctuating wind and density forcing, internal tides are not dynamically discrete from the near-subtidal, but a part of a continuum. Wavelet coherence as a function of scale and time of alongshore internal velocity and windstress. Vertical structures crossing the tidal band are indicative of a broad-band response to wind forcing that is often continuous across the tidal band.