Zheng Zeyu, Fu Yang, Liu Kaizhou, Xiao Rui, Wang Xiaohui, Shi Haibo
Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, PR China.
Key Laboratory of Network Control System, Chinese Academy of Sciences, Shenyang, 110016, PR China.
Sci Rep. 2018 Jul 2;8(1):9916. doi: 10.1038/s41598-018-27931-y.
Seawater conductivity is an important indicator of ocean electromagnetic properties and directly impacts the electromagnetic attenuation characteristics and phase distribution features of the ocean. Few studies have considered how the combined effects of salinity, temperature and pressure affect the vertical conductivity distribution and its formation mechanisms. Here, we analyse the vertical distributions of seawater conductivity from the sea surface to a maximum depth of 7062 m at five different locations. Electric conductivity profiles show similar vertical structures at all locations. Electric conductivity decreases with increasing depth first and then slowly increases from approximately 2000 m to the seabed. We observe an exponential relationship between the conductivity minimum and the water depth. At all five measurement locations, seawater conductivity measurements show a stable three-stage vertical distribution on logarithmic scales, with the middle stage satisfying a power law relationship. We analyse the vertical distribution of temperature in the second stage and investigate the relationship between temperature and conductivity. The results show that temperature also exhibits a power-law relationship with depth and a high linear correlation exists between temperature and conductivity. Our findings suggest that the vertical structure of conductivity is largely temperature dependent.
海水电导率是海洋电磁特性的重要指标，直接影响海洋的电磁衰减特性和相位分布特征。很少有研究考虑盐度、温度和压力的综合作用如何影响垂直电导率分布及其形成机制。在此，我们分析了五个不同位置从海面到最大深度7062米的海水电导率垂直分布。电导率剖面在所有位置都显示出相似的垂直结构。电导率首先随深度增加而降低，然后从大约2000米到海底缓慢增加。我们观察到电导率最小值与水深之间存在指数关系。在所有五个测量位置，海水电导率测量在对数尺度上呈现出稳定的三阶段垂直分布，中间阶段满足幂律关系。我们分析了第二阶段温度的垂直分布，并研究了温度与电导率之间的关系。结果表明，温度与深度也呈现幂律关系，且温度与电导率之间存在高度线性相关。我们的研究结果表明，电导率的垂直结构在很大程度上取决于温度。
