白令海是连接太平洋、北冰洋唯一要道,经济、军事地位极其重要。利用中国第5次北极科学考察CTD（Conductivity,Temperature,Depth）数据,在分析白令海西部小区域水文环境基础上,结合大陆坡地形,利用UMPE（University of Miami Parabolic Equation）抛物方程模型模拟声传播特征,并利用Bellhop射线声学模型分析其形成的物理机制。陆坡区域受流混合影响,50~350 m形成低温、低盐水团。声波沿陆坡向深海传播时,声能向500 m以上汇聚,次表层50 m左右形成声道,深层为声影区;声波沿陆坡向浅海传播时,50 m左右出现声道,深层传播损失较大,无声影区;＂斜坡增强效应＂使得声源置于浅水海域时,50 m声道强度大于声源置于深水海域。
The Bering Sea is the only channel connecting the Pacific Ocean and the Arctic Ocean, which is of great economy and military significance. The discussion in this paper is based on the CTD data from Chinese Fifth Arctic Research Expedition, and the characteristics of the area in the west of Bering Sea are analyzed. The acoustic transmis-sion propagation feature is simulated by UMPE model, and Bellhop model is used to explain it. Low temperature and salt water mass exists between the layers of 50-350m over the continental slope, resulted from vertical mixture. When the acoustic wave transmits along the slope from shallow-water to deep water, acoustic energy gathers to the upper 500 meters layer, underwater track appears in about 50 meters, the deep layer is shadow zone; When the acoustic wave transmits in the opposite direction, underwater track appears in about 50 meters, the transmission loss in deep layer is big with no shadow zone existing. Comparing the conditions as the source is putted in shallow water with in deep wa-ter, acoustic channel in 50m of the former is stronger due to “slope swelling phenomenon”.
the Bering Sea
characteristics of acoustic transmission
University of Miami Parabolic Equation model