1000-km range 2 dimensional ocean acoustic tomography near Japan

Abstract

1000-km range (62 1-km) 2-dimensional Qcean Acoustic Tpmography (OAT) was conducted in the west of North Pacific Ocean near Japan. Low frequency acoustic source (200 Hz) was moored just below the sound channel. Arrival signals from upper direction and lower one were separated by a beam forming technique. Stochastic inverse method was applied to the estimation of the sound speed perturbation. The expansion functions for horizontal and vertical direction were rectangular functions and empirical orthogonal functions (EOFs) respectively. The correlation of the sound speed anomaly was also included in the analysis. The results show that the characteristic pattern of cold-core rings observed in the temperature field with XBT was reproduced by the objective analysis process and the parameters.

Dynamic estimation of the sound-speed field in Mediterranean coastal waters

“…A straightforward range-dependent decomposition uses a rectangular functions basis, as in [6], [9]. In this parameterization, each rectangle (subregion) is independent from the others, enabling the introduction of any a priori knowledge of the spatial covariance in the inversion scheme.…”