Fig. 3: Current velocities and wake tracing around the O2 from fine-scale ADCP transects.

Fine-scale ADCP transect lines consisting of one upstream line and several lines downstream of the O2 marked by continuous black lines. All plots show ADCP-derived depth-averaged horizontal velocity coloured by magnitude (ms⁻¹) (left) and backscatter coloured by backscattering strength (Sv; dB re 1 m⁻¹) (right) rotated to the local coordinate system with the origin at the O2 location (X,Y) = (0,0), aligned with the mean flow direction and gridded at 1D. The streamlines (red), released at intervals of 2D cross-stream and 2D downstream of the O2, show the behaviour of the actual flow cross- and downstream of the O2 while the vectors (scale of 1 ms⁻¹ shown by red vector on the top right of each plot) show the difference in local flows relative to the average of the inflow region (orange in upstream lines). The O2 location is marked with a circle (magenta) and Eday is located towards the Y positive direction. A Ebb flow transect (14/04/2022, T5, mean ebb velocity = 2.6 ms⁻¹), (B) Ebb flow transect (17/04/2022, T5, mean ebb velocity = 2.8 ms⁻¹), and (C) Flood flow transect (17/04/2022, T1, mean flood velocity = 3.2 ms⁻¹).