琼东陆架海湍流混合的观测研究

发布时间：2018-01-29 10:08

本文关键词： 混合陆架海观测参数化方案琼东　出处：《广东海洋大学》2015年硕士论文　论文类型：学位论文

【摘要】：湍流混合是海洋中重要的物理过程之一,对海洋中物质的交换、能量的输运起着关键作用。陆架海是人类生存和发展的重要海域,复杂的地形与丰富的动力过程是控制和影响陆架海混合的重要因素。本文利用2012年2月和7月冬夏两季在海南岛以东两个航次的温度、盐度、流场和微尺度观测资料,揭示了琼东陆架海湍流混合的空间分布和季节变化特征,对比分析了不同混合参数化模型在该海域的适用情况,并提出了适用于琼东陆架海的混合参数化模型。对观测数据分析发现琼东陆架海的混合具有明显的季节变化特征,夏季琼东陆架海的混合较弱,平均耗散率1×10-9-1,平均混合率1×10-62-1,低于大洋的背景值;冬季时混合增强,平均耗散率1×10-8-1,平均混合率为1×10-42-1。夏季上升流使得等密线抬升,近海层结增强,平均层结(N2)为3.2×10-4-2,而冬季时的平均层结(N2)仅有3.2×10-5-2,比夏季小了一个量级。层结的变化是影响琼东陆架海混合冬强夏弱的重要因素。基于层结和剪切数据,利用Gregg1989(G89)、Kunze1990(K90)以及MacKinnon和Gregg2003(MG03)三种参数化模型对琼东陆架海的混合率和耗散率进行模拟,结果显示G89和K90模型结果明显比观测值大1个量级以上,MG03模型与观测值相对接近,另外,三种模型对冬季的模拟值与观测值的偏差小于夏季时的偏差,说明夏季上升流对混合机制有较大影响。针对夏季观测,我们提出夏季琼东陆架海混合的新参数化方案为ε=10-6.3344?1.103?0.3008。关于琼东陆架海湍流混合的机制以及参数化方案的改进还需进一步研究。
[Abstract]:Turbulence mixing is one of the important physical processes in the ocean, which plays a key role in the exchange of matter and energy transport in the ocean. Shelf sea is an important sea area for human survival and development. Complex topography and rich dynamic processes are important factors to control and influence the mixing of shelf and sea. In this paper, the temperature and salinity of two voyages east of Hainan Island in February 2012 and July are used. The characteristics of spatial distribution and seasonal variation of turbulent mixing in the eastern shelf sea of Qiongdong are revealed, and the applicability of different mixing parameterized models in the sea area is compared and analyzed. A mixed parameterized model suitable for the East Hainan Shelf Sea is proposed. The analysis of the observed data shows that the mixing of the East Jongdong Shelf Sea has obvious seasonal variation characteristics, and the mixing of the East Hainan Shelf Sea is weak in summer. The average dissipation rate is 1 脳 10-9-1 and the average mixing rate is 1 脳 10-62-1, which is lower than the background value of the ocean. The average dissipation rate is 1 脳 10 ~ (-8) -1 and the average mixing rate is 1 脳 10 ~ (-42-1) in winter. The average stratification N _ (2) is 3.2 脳 10 ~ (-4) ~ (-2), while in winter it is only 3.2 脳 10 ~ (-5) ~ (2). The variation of stratification is an important factor affecting the strong and weak winter in the east shelf sea. Based on stratification and shear data, Gregg1989 / G89 is used. Kunze 1990 K90) and MacKinnon and Gregg 2003 MG03) were used to simulate the mixing rate and dissipation rate of the East Hainan Shelf Sea. The results show that the results of G89 and K90 models are more than 1 order of magnitude larger than the observed values. The MG03 model is relatively close to the observed values. The deviation between the simulated and observed values of the three models in winter is smaller than that in summer, which indicates that the summer upwelling has a great influence on the mixing mechanism. We propose a new parameterization scheme for the sea mixing in the east shelf of Qiongdong in summer, which is 蔚 ~ (10) -6.3344? 1.103? 0.3008. The mechanism of turbulent mixing and the improvement of parameterization scheme need further study.
【学位授予单位】：广东海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P714

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