Transient Ice Events of Underwater Ambient Noise in the Arctic Ocean

A large number of transient ice events exist in underwater ambient noise in the Arctic Ocean, and they are believed to be the main contributor to underwater noise different from contributors in other oceans. This paper studied the underwater ambient noise (CHINARE18 and CHINARE20) recorded during the 9th Chinese National Arctic Research Expedition and the 11th Chinese National Arctic Research Expedition. The time-frequency analysis of two 7-s-long ice noise samples in the two experiments shows that ice transient events have impulsivity and wide spectrum. The statistical result of transient ice events in different frequency bands reveals that these events mainly contribute to the high-frequency component of under-ice ambient noise. It can be seen in the power spectrum that transient energy is apparent in the 90th and 99th percentile curves. Due to the influence of ice transient events, the CHINARE18 has obvious fluctuations in the spectral kurtosis in a certain frequency band (4kHz-8kHz).