Velocity Measurements in the Deep Western Boundary Current of the South Pacific

Abstract

IN their schematic theory of the deep ocean circulation, Stommel and Arons¹ require deep western boundary currents in each of the world's oceans as the means by which cold deep water is transported from polar regions to middle and low latitudes. These have been measured directly in the North Atlantic², inferred from the density field and property distributions in the South Atlantic³, and, most recently, detected in similar fashion in the South Pacific, just east of New Zealand and the Kermadec Ridge, during the occupation of transpacific hydrographic sections along latitudes 28° S and 43° S ⁴. Subsequently, Reid⁵ has made direct current measurements near the bottom in the narrow channel at about 9° S, 169° W, which connects the deep central basins of the North and South Pacific. These demonstrated a northward flow with near-bottom speeds of 5–15 cm/s which is presumably derived from the deep boundary current to the south.