Title: Multipath structure of the typical under-ice sound channel in the Arctic: theory and experiment

Author(s): LIU Chonglei; HUANG Haining; YIN Li; LIU Na; WEI Chonghua; LI Qihu;

Affiliation(s): Institute of Acoustics, Chinese Academy of Sciences; University of Chinese Academy of Science; The First Institute of Oceanography, SOA

Abstract: Considering the typical acoustic environment of the Arctic, this paper proposes a method based on OASES-Bellhop coupled model to rapidly analyze the multipath structure of the under-ice sound channel. Firstly the proposed model refers to ice plate as stratified elastic media with some roughness. Secondly, it uses the perturbation method and Kirchhoff approximation theory to solve the scattering loss due to the sea ice inhomogeneity. Finally, the model predicts the multipath structure of the under-ice channel through Ray theory. The results of the numerical simulation and experiment indicate that the typical Arctic sound channel presents multipath structures due to the sea ice and seabed in the range of 6 km, respectively. The sea ice reflection paths are stable, with a short multipath spread within 14 ms. The seabed reflection paths have relatively weak strength. The proposed OASES-Bellhop coupled model successfully predicts the amplitude and delay of the multipath structure with small error, which indicates the proposed model is able to analyze and predict the multipath structure of the observed acoustic environment in experiment.