Measurements from bottom-mounted acoustic vector sensors, deployed seasonally between 2008 and 2014 on the shallow Beaufort Sea shelf along the Alaskan North Slope, are used to estimate the ambient sound pressure power spectral density, acoustic transport velocity of energy, and dominant azimuth between 25 and 450 Hz. Even during ice-free conditions, this region has unusual acoustic features when compared against other U.S. coastal regions. Two distinct regimes exist in the diffuse ambient noise environment: one with high pressure spectral density levels but low directionality, and another with lower spectral density levels but high directionality. The transition between the two states, which is invisible in traditional spectrograms, occurs between 73 and 79 dB re 1 μPa²/Hz at 100 Hz, with the transition region occurring at lower spectral levels at higher frequencies. Across a wide bandwidth, the high-directionality ambient noise consistently arrives from geographical azimuths between 0° and 30° from true north over multiple years and locations, with a seasonal interquartile range of 40° at low frequencies and high transport velocities. The long-term stability of this directional regime, which is believed to arise from the dominance of wind-driven sources along an east–west coastline, makes it an important feature of arctic ambient sound.

中文翻译：

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开放水域北冰洋噪声方向性和传输速度的测量

2008 年至 2014 年间在阿拉斯加北坡浅波弗特海架上季节性部署的底部安装声矢量传感器的测量结果用于估计环境声压功率谱密度、能量的声传输速度和 25°之间的主导方位角。和 450 赫兹。即使在无冰条件下，与美国其他沿海地区相比，该地区也具有不同寻常的声学特征。在漫射环境噪声环境中存在两种不同的状态：一种具有高压谱密度水平但方向性低，另一种具有较低的谱密度水平但具有高方向性。两种状态之间的转变在传统频谱图中是不可见的，发生在 73 到 79 dB re 1 μPa ^{2 之间}/Hz 在 100 Hz，过渡区出现在较高频率的较低频谱水平。在很宽的带宽内，高方向性环境噪声在多年和位置上始终来自真北 0° 到 30° 之间的地理方位角，在低频和高传输速度下具有 40° 的季节性四分位间距。这种定向状态的长期稳定性被认为是由沿东西海岸线的风驱动源的主导地位引起的，使其成为北极环境声音的一个重要特征。