Influence of turbulent mixing on the intrusion interleaving in the central part of the Equatorial Pacific

Abstract

We analyzed CTD data of high spatial resolution in order to study the equatorial interleaving in the central part of the Pacific Ocean. The CTD section across the equator (from 2° S to 1° N along 176° 16′ W) showed the existence of highly-correlated intrusion layers; the correlation was distorted in the region of 0°12′ N-0° 15′ N. In the central part of the region, virtually no intrusion interleaving was observed. At the boundaries of the region, distortions of the coherence were accompanied by an increase in their vertical scales and by a decrease in the intensity of the anomalies in the vertical profiles. A suggestion was put forward that the effect recorded is caused by the mixing in the turbulent wake beyond Baker Island, which is located 10 nautical miles west of the study region. In order to describe the particularities of the intrusive interleaving, we considered a model of interleaving on a ß-plane with account for double diffusion, turbulent mixing, and horizontal shear of the zonal flow. The theoretical results obtained were used to explain the recorded particularities of the intrusive interleaving. Copyright © 2004 by MAIK "Nauka/Interperiodica" (Russia).