Characterization of Arctic noise using acoustic indices and its response to sea ice changes

With global warming, the continuous changes in Arctic sea ice have significantly altered the acoustic environment beneath the ice; however, quantifying how environmental factors influence under-ice noise remains a key challenge. Based on data from two acoustic moorings deployed at the Chukchi Plateau in the Arctic from September 2017 to November 2019, the relationship between Arctic under-ice noise and the environment was explored. This study applies the acoustic entropy index (AEI) and acoustic complexity index (ACI) to quantitatively assess under-ice ambient noise. By analyzing noise data under different sea ice concentration conditions, it was found that AEI is positively correlated with the characteristic exponent α, sea surface wind speed, and sea surface temperature, and negatively correlated with sea ice concentration, reflecting the combined effect of Arctic meteorological factors and sea ice conditions on under-ice noise. The relationship between ACI and the above parameters is opposite to that of AEI, mainly reflecting impulsive noise events caused by sea ice rupture. These results verify the feasibility of acoustic indices as tools for under-ice environmental monitoring, which has important applications for Arctic acoustic ecological assessment and climate change research.