The ambient noise energy motion in the near-surface layer in ocean wave-guide

Abstract
The results of measurements of scalar - vector characteristics of the ambient noise acoustic field in deep ocean areas over the range of 1-800 Hz are presented. The subject of investigations were the ambient noise energy in the part of the ocean wave-guide that lied between the surface and the underwater sound channel axis lying at the depth of the order of 1200 m. A telemetric drifting autonomous system with combined receivers was used in the investigations. A combined receiver consisted of a scalar receiver (hydrophone) and a vector receiver of three components particle velocity. Our studies revealed that ambient noise energy transport in the vertical plane occurred in three main directions : 1) over the range of 1-12 Hz it proceeded from the underwater sound channel axis to the ocean surface in the angles range of 0°-30° ; 2) over the range of 32-141 Hz it proceeded from the sea surface to the underwater sound channel axis in the angles range of 0°-40° ; 3) over the range of 282-800 Hz noise energy flux made an angle between 10° and 30° with z axis, and its horizontal component coincided with wind wave propagation direction over the range of 447-800 Hz. Over the range of 282-355 Hz horizontal component of the noise energy flux coincided with ripple direction and over the range of 562-800 Hz it did with the propagation direction of wind surface waves.