Acoustic Description of South Atlantic Ocean Warm Core Eddy

摘要

This document contains the viewgraph presentation which investigates the thermohaline/baroclinic scales of the meso-scale eddies associated within the Brazil Malvinas (Falkland) Confluence. One of the eddies investigated was a warm core anti-cyclonic eddy centered about 43 deg 50 min S and 54 deg 15 min W (18-19 October) with a diameter of 125 km. The XBT's and CTD's taken through the eddy were used with a range dependent acoustic prediction ray model (GRASS) to model a cross section of the eddy at 50 Hz comparing propagation loss with source depths of 25, 150, and 500 m and receiver depths of 25, 150, and 500 m. Comparisons were done propagating through the eddy, from the outer edge to the eddy interior, and from the interior to the outer edge. The results were compared with a no eddy, range independent situation. Results showed that due to the presence of a surface duct in the warm core eddy the greatest impact was found propagating a shallow source with a shallow receiver. No effects were seen below 300 m, similar to the North Pacific and Greeland Sea eddies.