Examination of 18 years of nearly continuous low frequency deep ocean ambient noise offshore Cape Leeuwin, Australia, finds evidence of a decreasing nonlinear trend suggestive of long-term cyclic dynamics. The nonlinear trend is found to be consistent with trends in oceanographic sea surface temperature, which are thought to drive changes in Antarctic sea ice extent. Assessment of oscillatory dynamics finds causal covariance between ambient noise levels and Indian Ocean sea surface temperature dipoles. Dynamics of annual ambient noise and Antarctic sea ice extent are examined suggesting a phase-locked relationship revealing nonlinear characteristics of the presumed dependence. Collectively, the hypotheses that deep water ambient noise dynamics in the Indian Ocean are influenced by Antarctic sea ice extent and melt dynamics and that linear models do not fully capture long-term ambient noise trends and dynamics are supported.

中文翻译：

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澳大利亚卢因角印度洋的低频环境噪声动态和趋势

对澳大利亚卢因角近海 18 年近乎连续的低频深海环境噪声的检查发现非线性趋势下降的证据表明长期循环动力学。发现非线性趋势与海洋海面温度的趋势一致，这被认为是驱动南极海冰范围变化的因素。振荡动力学评估发现环境噪声水平与印度洋海面温度偶极子之间的因果协方差。研究了年度环境噪声和南极海冰范围的动态，表明锁相关系揭示了假定相关性的非线性特征。总的来说，