Abstract for "The EBC-ARI Slope Array: Results from Year One"

An array of 5 subsurface current meter moorings was deployed from June 1992 - May 1993 over the continental slope just south of Point Arena CA to study the dynamics of California Current eddies and their interactions with the mean currents and bottom topography. The mooring configuration consisted of a diamond 20 km on a side spanning the 400 - 2600 m isobaths, with the central mooring in the middle. The instrumentation was concentrated at the 100, 150, 300, and 600 m depths. The data return was excellent with 18 of 19 current meter records returning complete records.

The goal of a coherent array apparently was achieved, with the major events appearing at all moorings. The observed currents were overwhelmingly poleward at all locations with vector means ranging from 13 cm/s (eastern mooring, 150m depth) to 2.8 cm/s (central mooring, 600 m depth). The strongest poleward flows occurred during January 1993 and exceeded 40 cm/s at 100 m depth at all but the central mooring, possibly reflecting the core depth of the California Undercurrent. There were only 3 episodes of sustained equatorward flow: A subsurface eddy event (centered near 300 m) during December 1992, a stronger, more barotropic eddy event which exceeded 600 m depth during April-May 1993, and a strongly surface intensified event, possibly wind driven, at the eastern mooring only, during March and April 1993. The temperature time series and spectral distribution of energy will also be discussed.

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