The Three-Dimensional Mapping of a Small Thermohaline Intrusion

Abstract

Abstract During the Mixed-Layer Experiment (MILE) at Ocean Station P in August-September 1977. a depth-cycling towed CTD was used to map intrusions below the seasonal thermocline. In a 10 km square two prominent minima in temperature and salinity were found to be 6?8 km long, 2 km wide and 7?15 m thick. A detailed survey of one of these showed that it had a tongue-like shape and sloped downward across isopycnal surfaces from its origin at a strong front in a corner of the mapped area. The characteristics of the intrusion in comparison with laboratory experiments make it probable that it originated by double-diffusive convection occurring in the frontal region.