摘要
利用WOA05气候态数据集和北黄海调查数据,应用BELLHOP高斯束射线模型分析了我国近海及西太平洋典型海区的混合层结构对表面声道中声传播特性的影响,结果表明:我国近海的混合层结构有显著的区域性和季节性变化;深海中主要表现为混合层深度变化,这种变化直接影响表面声道的空间分布,声波在混合层中的表面声道中传播与在混合层外的影区中传播产生的能量场差异较大;浅海中混合层深度与声速梯度的空间变化都很明显,声速梯度的增大和混合层的加深都能使更多声线以反转的形式传播,使表面声道声场增强。两组海上实验数据表明,在真实海洋中混合层可在短时间内出现生消变化或在局部海域出现非均匀分布。在浅海温跃层环境下,海-气边界特定的物理过程能够使混合层发生间歇性的变化,当表面声道出现时近表层声场明显增强。
Based on WOA05 climatological database and the measured hydrologic data in the northern Huanghai Sea,the effect of typical mixed-layer structures on the acoustic propagation in a surface duct environment in adjacent sea areas of China is discussed using the BELLHOP Gaussian beam model.The mixed-layer structures show distinct variations between different areas and seasons.In the deep sea,the mixed-layer depth is a main variable factor,which defines the vertical space of the surface duct.A obvious difference of acoustic energe level appears when the propagation occurs in a surface channel inside the mixed-layer compared with that in a shadow zone outside the mixed-layer.In the shallow water,the mixed-layer depth and the sound speed grads are both streaky.More reversal rays are involved when the sound speed grads enhancing or the mixed-layer depth deepening,which make the energe level in the surface duct increased.Two groups of measured data show that the mixed-layer depth may yield or fade suddenly with time and distribute asymmetrically with range.Under a thermocline enviroment in the shallow water,the acoustic energy level near the surface can be evidently raising when the surface duct comes into being in condition of some specific oceanographic phenomena in the air-sea boundary layer.
出处
《海洋学报》
CAS
CSCD
北大核心
2012年第1期79-89,共11页
关键词
混合层
声速剖面
表面声道
声传播
BELLHOP模型
mixed-layer
sound speed profile
surface duct channel
acoustic propagation
BELLHOP model
