Wintertime Current Meter Measurements from the East China Sea

Abstract

An array of three current meters were anchored on the continental shelf of the East China Sea during the last half of February 1975 as part of the Japanese Air Mass Transformation Experiment, AMTEX-75. The results indicate that the currents are dominated by the rotational semidiurnal M2 component superimposed on a slow mean drift to the northeast. Differences in direction of several days duration between two of the current meters suggest the presence of transient mesoscale eddies or meanders in the flow regime. Rotary spectra indicated that the tidal currents are characterized by a clockwise ellipse of eccentricity ≈0.6 and that there was some inertial energy present. The current rose for bandpassed velocity fluctuations (0.2?2 eph) was elongated in a direction 25?30° to the right of the wind direction indicative of Ekman veering.