Advanced Ocean Modelling: Using Open-Source Software

152 5 3D Level ModellingFig. 5.22 Exercise 24. Locations of Lagrangian floats, initially located south of y = 350 km, after120 days of simulationFindings presented here show an intrinsic coupling between the deep and surfaceflows in the western boundary region of the Atlantic Ocean. This suggests thatthe density-driven DWBC operates to intensify the wind-driven Western BoundaryCurrent in the north Atlantic Ocean; that is, the Gulf Stream and its extension, theNorth Atlantic Current. A number of recent research projects explore this couplingmechanism which is deemed to have a substantial impact on the climate of northernEurope on time scales of 10–20 years (Broecker, 1999).5.8.4 Additional Exercise for the ReaderRepeat this exercise with β = 0, yielding the so-called f plane. Does the β-effecthave a noticeable influence on the dynamics of the Deep Western Boundary Current?5.8.5 Improved Float TrackingFloat locations are defined as distances from the point of origin of the Cartesiancoordinate system. In this book, the point of origin is defined at the vertical velocitygrid point w at k = 1, j = 1 and i = 1, which is aligned with the sea surface.Prediction of the displacement of a float requires information of velocity in adjacentgrid points. To this end, the grid cell containing the float need to be identified and therest follows. The procedure is demonstrated here using the x-direction only. Analogrecipes apply for the other velocity components, noting that treatment for the vertical