WESTERN AND EASTERN BOUNDARY CURRENTS

Schematic Model of Boundary Currents

Explanation of Western Intensification Western Intensification from Beta effect Explanation of Western Intensification Coriolis constant Coriolis changing with latitude

Low Productivity in Western Boundary Currents Ocean Color Low Productivity in Western Boundary Currents - major pathway for heat, salt and nutrients transport to high latitudes - frontal processes of important ecological implications

General Origin and Path of Gulf Stream

Sea Surface Temperature image of the Gulf Stream, in yellow and orange Sea Surface Temperature image of the Gulf Stream, in yellow and orange. Data from the MODIS instrument on the Aqua satellite. Image provided by Norman Kuring, NASA/GSFC. (oceanmotion.org)

Complete View of the Gulf Stream Poleward transport of heat

Along-stream Momentum Balance U = 1 m/s, V = 0.1 m/s, W = 1x10-5 m/s, t = 4x105 s, Lx = 5x105 m, Ly =1x105 m, H = 500 m, f = 1x10-4 s-1, Ax = 10 m2/s, Az=1x10-3 m2/s Inertia, Coriolis, Pressure Gradient

Across-stream Momentum Balance U = 1 m/s, V = 0.1 m/s, W = 1x10-5 m/s, t = 4x105 s, Lx = 5x105 m, Ly =1x105 m, H = 500 m, f = 1x10-4 s-1, Ax = 10 m2/s, Az=1x10-3 m2/s Coriolis and Pressure Gradient = Geostrophy

Gulf Stream Eddies May 1997

Temperature cross-section of a cold-core ring in the Gulf Stream

Link to Gulf Stream Tutorial

KUROSHIO CURRENT (Black Water)

Long-term mean geopotential anomaly (converted to meters) relative to 1000 db (Hasunuma and Yoshida, 1978) Korea Japan China Philippines

Surface mean currents in the East China Sea derived from geopotential anomaly data from 1953-1984 (Qiu and Imasato, 1990). Korea Japan China Taiwan

with respect to 700 db. (Guo et al., 2003)

Velocity profile along the ASUKA line: Geostrophic calculation with a reference level at 2000 m in the deep area and at the bottom in the shallow area (S. Imawaki 1995) Contour interval is 0.1 m/s; shaded areas denote negative values.

Kuroshio path in 2000 (from the Bulletin of Oceanic Conditions, published by the Japanese Coast Guard)

EASTERN BOUNDARY CURRENTS

Weak Winds Strong Winds

PF = Polar Flow CJ = Coastal Jet GF = Geostrophic Flow (From Tomczak)