ASA 124th Meeting New Orleans 1992 October

2pAO9. A tomographic view of mesoscale activity in the Gulf Stream southern recirculation gyre.

David Chester

Woods Hole Oceanogr. Inst., Dept. of Phys. Oceanogr., Clark Lab., Rm. 358, Woods Hole, MA 02543

Paola Malanotte-Rizzoli

MIT, Cambridge, MA

Variability of the mesoscale eddy field in a region just south of the Gulf Stream has been monitored via acoustic tomography. For 10 months (November 1988 through August 1989), a pentagonal array of tomographic transceivers was situated in a region centered at 38(degrees)N, 55(degrees)W. The tomographic array was part of the eastern array of the SYNOP (SYNoptic Ocean Prediction) experiment. This region is one rich in mesoscale energy, with the influence of local Gulf Stream meandering and cold core ring activity strikingly evident. The tomographic data set has been analyzed and a view of the temperature, current velocity, and vorticity fields has been revealed. The signature of cold core rings is clearly seen in these sections. Spectra are estimated from the tomographic time series, and are shown to be consistent with concurrent current meter data. Second-order statistics, such as heat and momentum fluxes, are also estimated. The integrating nature of the tomographic measurement has been exploited to shed some light on the radiation of eddy energy from the Gulf Stream.