On the Origin of Eddies Discovered during the POLYMODE Local Dynamics Experiment

Abstract The intensive hydrographic survey conducted in 1978 as part of the POLYMODE Local Dynamics Experiment (LDE) revealed a large number of anomalous water parcels at various depths near 31°N, 70°W in the Sargasso Sea. From analyses of the mean water properties in the LDE survey, Lindstrom and Taft have prepared a census of discrete features that have statistically significant anomalies of salinity, oxygen or potential vorticity. The present analysis utilizes the climatological (annual mean) North Atlantic dataset compiled by Levitus to identify the large-scale distribution of salinity and oxygen on specific potential density surfaces. This technique has revealed distinct geographic origins for the majority of the 23 LDE features analyzed. Nine shallow features residing between 25.8 and 26.4 sigma-theta were found to have varied origins: two from the eastern Atlantic, three from the Gulf Stream, two from the central Sargasso Sea, and two were indeterminate with the available data. Four of six upper-th...