Extended Data Fig. 7: Linear regression of the centres of mass of potential density anomaly, the gradient of potential density anomaly over time and estimates of upwelling velocity.
From: Observations of diapycnal upwelling within a sloping submarine canyon
(a) Weighed linear regression (solid blue line) and unweighted linear regression (solid red line) of the centres of mass in potential density anomaly space (black circles). Error bars show standard deviations of dye-weighted density for each transect. The residual standard error of the fit is denoted by the shaded region. Dashed lines show the fits given the standard error on the slope and intercept. The coefficient of determination R2 for the weighted fit is 0.852 and for the unweighted fit is 0.587. (b) Centres of mass in potential density anomaly gradient space (black circles) and standard deviation for each transect (error bars). The solid blue line shows the weighted average of the centres of mass. The standard error of the average is 2.5 × 10−5 kg m−4 and is smaller than the line width. (c) Estimates of upwelling velocity between subsequent pairs of centres of mass (black circles). Lines denote the upwelling values estimated using different methods: the weighted linear regression (blue), the unweighted linear regression (red), the difference between average height above bottom between the first and last transect (orange), the pairwise estimates in the difference between average height above bottom (green) and the average over all pairwise estimates of the upwelling velocity (black).
