Fig. 3: Observations of dye concentration demonstrating upwelling of dye in density space.
From: Observations of diapycnal upwelling within a sloping submarine canyon
a–c, Dye concentration as measured during transects at 2.5 hours (a), 15 hours (b) and 47.5 hours (c) after release. Dye concentration is shown on a logarithmic scale in ppb in colour, isotherms whose mean depths are separated by 10 m are shown with thin black contours and the χ =1 × 10−7.5 °C² s−1 contour is shown in blue on each panel denoting regions of enhanced turbulent mixing. The thick black contours indicate reference conservative temperatures (CT) 3.7 °C, 3.85 °C and 4.05 °C for a–c, respectively. The threshold of dye concentration detection for the fluorometer onboard the FCTD is 0.06 ppb. Scale bars in a and b are 0.5 km and denote an estimate of the horizontal length of the transects. d, Temperature–salinity diagram of the centre of mass for each transect. Scatter points are coloured by time since the dye release in hours and the size of the data point indicates the average concentration during the transect. Scatters with thick outlines are labelled a, b and c, and correspond to the examples shown in a–c, respectively. The temperature and salinity at which the dye was released is marked with the pink star. The grey contours show lines of constant potential density anomaly in kg m−3. See Extended Data Fig. 5 for all transects and Extended Data Fig. 6 for the full temperature–salinity distribution of each transect.
