Evidence for Low-Frequency Wind-Driven Currents in the FASINEX (Frontal Air-Sea Interaction Experiment) Region

摘要

Two subsurface current meter moorings were deployed for a 20 month period in locations bracketing the main FASINEX array (F1 at 28 deg N, 70 deg W and F12 at 25.5 deg N, 70 deg W). Each mooring had seven VACMs (Vector Averaging Current Meters) deployed at depths between 160 and 4060 m. Some fairly strong observational evidence has been found for the forcing of current fluctuations by variations in the wind stress curl over the ocean. Response is to both local and nonlocal forcing, is baroclinic in character, and becomes less coherent at higher frequencies. A linear stochastic model of the ocean's response to fluctuating forcing shows that some of these characteristics can be qualitatively rationalized, although the low model energy levels (in comparison to observations) seem particularly troublesome. Keywords: Ocean currents; Air water interactions; FASINEX (Frontal air sea interaction experiment); Ocean circulation models. North atlantic ocean. Reprints. (edc)