黑潮-亲潮交汇区柔鱼渔场温盐垂直结构反演实验

与渔业生产数据时空匹配的长时间序列三维实时海洋环境 数据的缺乏，一直是制约渔业海洋学深入研究的重要因素之一。本文基于数据同化的思想，采用梯度依赖最优插值方法，以黑潮-亲潮交汇区柔鱼渔场为例，利用 Argo观测数据，进行了渔获点上温盐垂直结构的反演 实验，在理论检验、与实测数据对比验证该方法有效性的基础上，初步探讨了渔场区的温盐特征及其与柔鱼渔获量的关系。结果表明，通过梯度依赖方法构建的温度均方根误差小于1℃，盐度小于0.4；与淞航号实测数据的温、盐绝对误差分别在0.25℃和0.27以内。2018年8月和10月的统计分析表明，柔鱼在5m深度的适宜温度分别为16℃和14℃，50m约为9~ 12℃ ，并且柔鱼趋于在低盐海域活动；各水层温度与渔获量均大致呈曲率不同的指数函数关系，且渔获点存在明显跃层，跃层强度变化越大，渔获量随机性也越大，渔获量跃层强度在0.4℃/m左右时渔获量相对稳定。这些结果进一步验证了该方法在构建环境垂直结构方面的可行性，其可为渔场环境的深入研究提供必要的技术手段。

Reconstruction experiment of temperature and salinity vertical structure of squid fishing ground in Kuroshio-Oyashio confluence area

The lack of long-time series three-dimensional real-time environmental data spatially and temporally matching with fishery production data has always been one of the important factors restricting the in-depth study of fishery oceanography. Based on the idea of data assimilation, this paper adopts the gradient-dependent optimal interpolation method to carry out the real-time inversion experiment of the vertical structure of temperature and salinity at the catch point by taking the squid fishing ground in the Kuroshio-oyashio confluence area as an example and using Argo observation data. On the basis of theoretical tests and comparisons with the measured data to verify the validity of the method, the characteristics of temperature and salinity in the fishing ground area and its relationship with the catch of squid are preliminarily discussed. The results showed that the root mean square error of temperature constructed by the gradient-dependent method was less than 1 ℃ and the salinity was less than 0.4. The absolute errors of temperature and salinity with the measured data of Songhang were within 0.25℃ and 0.27, respectively. The vertical structure analysis in August and October 2018 showed that the suitable temperatures for the squid at depth of 5 meters were 16 ℃ and 14 ℃, respectively, and about 9~12 ℃ at depth of 50 meters. Moreover, the squid tended to be active in low salinity waters. The relationship between the temperature of each water layer and the CPUE was roughly an exponential function with different curvatures, and therewas an obvious thermocline at the catch point. The greater the variation in the strength of the thermocline, the greater the randomness of the CPUE. When the strength of the thermocline is around 0.4 ℃/m, the CPUE is relatively stable. These results further verify the feasibility of this method in constructing the vertical structure of the environment, which can provide the necessary technical means for the in-depth study of the fishing ground environment.