Annual Acoustic Propagation Characteristics in the Typical Shallow-Water Topography of the Chukchi Sea

This study systematically analysed the seasonal variation patterns of acoustic propagation characteristics in the unique shallow-water ice-water-seafloor coupled acoustic environment of the Chukchi Sea in the Arctic. The model, which is finite element-based, was developed to comprehensively consider four environmental factors. These factors are as follows: seasonal ice melting and growth, variations in sound velocity profiles, seafloor topography, and sediment types. The results show that the underwater acoustic propagation characteristics in the Chukchi Sea are significantly influenced by the interplay between the source frequency, depth, and seasonal environmental conditions. Low-frequency sound waves are dominated by the waveguide cutoff effect, which is formed by the coupling between the winter ice cover and the seafloor., causeing acoustic energy to leak rapidly in a non-modal form. During the spring ice-melting period, mid-frequency sound waves experience a reduction in propagation loss of more than 10 dB compared with other seasons due to reflection from the ice–water mixed interface. High-frequency waves manifest intricate interference patterns, which are governed by waveguide constraints and interface reflections. Up-slope topography ntensifies acoustic energy dissipation, and its coupling effect with the ice cover leads to a sharp increase in propagation loss in winter. The present study elucidates the physical mechanisms underlying spatiotemporal variations in the shallow-water acoustic field of the Chukchi Sea, thereby providing theoretical foundations for the deployment of polar hydroacoustic equipment and channel prediction.