台风“天秤”对两种深海声道下声传播的影响

将Argo浮标资料与卫星遥感再分析数据相结合,调用基于抛物方程算法的RAM(Range-dependent Acoustic Model)模型,研究了2012年第14号台风“天秤”对不完整深海声道(3 000 m)和完整深海声道(5 500 m)两种水深条件下声传播特性的影响。结果显示:台风对海水的影响局限于表层水体,具体为混合层加厚,混合层内温度梯度接近于零,声速在混合层内正梯度分布;混合层下方一定深度的水体增温,相应的声速也增大。声源在混合层内时,主要对海表层的声传播产生影响,两种水深条件下均出现表面波导声传播模式以及泄漏模式。声源在混合层以下时,不完整深海声道条件下台风使得会聚区向着声源方向靠近;完整深海声道条件下台风对会聚区的位置影响不明显,但声波的翻转深度增加近500 m。

Effects of typhoon Tembin on underwater acoustic wave propagation in two kinds of deep sound channel

Using RAM (Range dependent Acoustic Model) model which was based on parabolic equation algorithm and combined Argo floats with multi-satellite data, effects of typhoon on acoustic propagation characteristics for incomplete deep-sound channel(3 000 m) and complete deep-sound channel(5 500 m) were researched. Results show that the influence of typhoon on sea water is confined in surface layer, which is characterized by the thickening of the mixed-layer, zero temperature gradient and positive sound speed gradient in the mixed-layer. At a certain depth below the mixed-layer, the water temperature increases, and the corresponding sound speed increases. When the sound source is placed in the mixed-layer, sound propagation in sea surface layer will be affected, the surface waveguide sound propagation and leakage modes appear in both incomplete and complete deep-sound channels. When the source is under the mixed layer, typhoon makes the convergence zone close to the sound source under the condition of incomplete deep-sound channel.Under the condition of complete deep-sound channel, the disturbance of typhoon on the location of convergence zone is not obvious, but the flip depth of the sound wave increases nearly 500 m.