The sound-speed distribution in ring BOB present during cruise 011 of R/V Endeavor (July-August 1977) has been examined on the basis of CTD and XBT observations. Sound-speed values for the XBTs have been computed utilizing a regression analysis for salinity on the hydrographic data and Wilson's sound-speed formula. In addition to the characteristic low sound-speed lens associated with the ring core, the resolution obtained with the XBT observations has revealed a near-surface high sound-speed halo, surrounding the core, in the region of the encircling Gulf Stream remnant. The halo is present between the depths of 50 to 150m and represents a deviation of approximately 20 m/s relative to ring center at 100 m. The azimuthal deviations of sound speed from circular symmetry are presented in terms of observations taken on cruise 008 of R/V Endeavor(May 1977). These perturbations are related to quasi-geostrophic wave structures within the ring which may be stationary or rotate around the ring. The high sound-speed halo, low speed lens, shape perturbations, and translation generate a complex acoustic environment within cyclonic rings.
ASJC Scopus subject areas
- Arts and Humanities (miscellaneous)
- Acoustics and Ultrasonics