ASA 127th Meeting M.I.T. 1994 June 6-10

1pUW4. Ambient noise vertical and horizontal directionality during SWellEx-1.

W. S. Hodgkiss

G. L. D'Spain

A. M. Richardson

Marine Phys. Lab., Scripps Inst. of Oceanogr., Mail Code 0701, La Jolla, CA 92093-0701

SWellEx-1 (Shallow Water evaluation cell Experiment #1) was carried out in August 1993 west of Point Loma in approximately 200 m of water. During SWellEx-1, a MPL 48-element vertical array was deployed from the R/P FLIP. In addition, the McDonnell--Douglas two-dimensional seafloor array (USTS) was deployed nearby and cabled back to FLIP for data recording. As well as along-slope and cross-slope source tow events, several days of ambient noise data were collected with both arrays. Shipping noise varied substantially during this period due to fluctuations in traffic patterns. The focus of this paper is on the temporal evolution of ambient noise vertical and horizontal directionality during SWellEx-1. For selected data segments, dominant shipping sources will be identified geographically and the observed vertical and horizontal directionality related to source-array propagation characteristics. [Work supported by ONR, Code 321.]