| 声跃层结构变化对深海汇聚区声传播的影响 |
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| 引用本文： | 张旭,张永刚,董楠,张健雪.声跃层结构变化对深海汇聚区声传播的影响[J].台湾海峡,2011,30(1):114-121. |
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| 作者姓名： | 张旭 张永刚 董楠 张健雪 |
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| 作者单位： | 1. 海军大连舰艇学院,辽宁,大连,116018
2. 中国海洋大学海洋环境学院,山东,青岛,266003 |
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| 摘 要： | 根据射线理论建立了线性声速结构条件下的声跃层强度与深海汇聚区关系模型,用最小位移角讨论了海洋环境变化（如声跃层强度变化、声跃层位置变化及季节性跃层生消等）与汇聚区距离和宽度变化的相关性.结果表明,声跃层的结构变化对汇聚区特征影响很大.声跃层强度增大使汇聚区向远离声源的方向变化,跃层强度每增加0.01 s-1对应的汇聚区位移增大约为3.5～5.0 km.声跃层位置变化对汇聚区的影响小于声跃层强度,与两层结构的声速剖面相比,上行结构使汇聚区向靠近声源的方向变化,声跃层上升200 m对应的汇聚区位移减小约为1.0～1.5 km,声跃层越浅,汇聚区距离越近;下行结构使汇聚区向远离声源的方向变化,混合层加深200 m对应的汇聚区位移增大约为1.0～1.5 km,混合层越深,汇聚区距离越远.季节性跃层的生消使近表层有负梯度、零梯度和正梯度的变化.负梯度结构的变化规律与两层结构条件下的声跃层强度变化类似,但对汇聚区的影响程度相对较小;正梯度结构使汇聚区在近表层出现表面声道,梯度值的增强将使汇聚区向靠近声源的方向变化.
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| 关 键 词： | 海洋声学 声跃层 声速剖面 汇聚区 最小位移角 |
Effects of thermocline structure variations on acoustic propagation in convergence zone |
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| ZHANG Xu,ZHANG Yong-gang,DONG Nan,ZHANG Jian-xue.Effects of thermocline structure variations on acoustic propagation in convergence zone[J].Journal of Oceanography In Taiwan Strait,2011,30(1):114-121. |
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| Authors: | ZHANG Xu ZHANG Yong-gang DONG Nan ZHANG Jian-xue |
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| Institution: | 1.Dalian Naval Academy,Dalian 116018,China;2.Institute of Marine Environment,Ocean University of China,Qingdao 266003,China) |
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| Abstract: | A model that provides a connection between deep-ocean thermocline intensity and convergence zone(CZ) phenomena is presented based on ray theory under the condition of a two layer linear sound speed profile(SSP).The relationship between environmental variability(such as main thermocline intensity,main thermocline depth and seasonal thermocline structure) and distance and width of CZ was analyzed using a new variable of minimum displacement angles(MDA).The results showed that the thermocline structure greatly influences CZ features.An increase in the thermocline intensity causes the CZ to shift away from the source,and the increment of CZ can be 3.5～5.0 km if the thermocline intensity increases at a rate of 0.01 s-1.The thermocline position has a smaller influence on CZ than thermocline intensity.In comparison with two-layer linear SSP,the CZ shifts close to the source when an up-type structure is used.The decrement of CZ can be 1.0～1.5 km in thermocline conditions deepening to 200 m.In contrast,if the CZ shifts away from the source with a down-type structure,the increment of CZ can be 1.0～1.5 km in mixed-layer conditions deepening to 200 m.The CZ is nearer when the thermocline becomes shallow with an up-type structure,and it is further when the thermocline becomes deep with a down-type structure The existence of a seasonal thermocline causes complicated variabilities in a certain layer near the ocean surface,including a negative gradient,zero gradient,and positive gradient.The relationship between seasonal thermocline intensity and CZ with negative gradient SSP is similar to that of the main thermocline,but to a smaller degree.A surface duct is formed with a positive gradient SSP,and the increase in the gradient causes the CZ to be near the source. |
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| Keywords: | ocean acoustics thermocline sound speed profile(SSP) convergence zone(CZ) minimum displacement angle(MDA) |
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