Fig. 4: Laurentian Channel horizontal SF5CF3 tracer dispersion and corresponding 1D model simulations.

Map (a) shows Laurentian Channel stations from both legs and an along-channel axis with x = 50 km spacing between individual points on the axis. Plot (b) shows station-wise vertically integrated tracer Ij as a function of along-channel distance: blue is used for Leg 1, and red for Leg 2. The dashed lines represent a 50 km overlapping window mean for Leg 1 and a 75 km overlapping window for Leg 2, both with a 50% window overlap. In (c), \(I{\prime}\)(x, t) is estimated from the 1D pipe model by substituting \(\overline{u}\) and \(\overline{{\kappa }_{{{{{{{{\rm{h}}}}}}}}}}\) into Equation (4). Plot (d) shows modeled \(I{\prime} (x,t)\) transit time distributions at points along the channel, where line colors correspond to colored axis markers in map (a).