渤海水龄及其多源组分分析的数值研究

发布时间：2019-03-02 21:05

【摘要】：水龄作为理解水体动力过程与水体物理化学或者生物过程之间关系的辅助变量，对于物质在水体中的输运过程以及交换过程有重要意义。对于某一特定水域来说，其水体来源往往不是单一的，因此对水域“多源”水龄的研究是很必要的，而目前关于这方面的研究比较少。本文以渤海为例，基于三维普林斯顿海洋模型（POM）模拟的渤海水动力场，利用CART（the Constituent-orientedAge andthe Residence time Theory）理论对渤海水龄进行模拟研究，定量分析了渤海的多源（河流水、降水、外海水）组成，通过对渤海开边界条件的选择讨论再返回过程对渤海水龄的影响，并通过过一系列的数值实验分析了控制渤海“多源”水龄的主要动力机制以及各水源之间相互作用对水龄的影响。渤海水是指由渤海所有来源水（河流水、降水、外海水）共同组成的多源水体，其中，河流水、外海水和降水分别占渤海全部水体体积的12.28%、77.24%和10.48%，，其体积平均水龄分别为：1271天、1969天、1269天。渤海水在渤海中的体积年平均水龄为1810天，随着离渤海海峡距离的增加，渤海水龄逐渐增大。在渤海环流的影响下，渤海水龄在空间分布上存在着较明显的季节变化，尤其在河口区域附近。随着季节性跃层的出现，渤海水龄垂向分布上也出现一定的分层，且离河口越近渤海水龄的垂向分层越明显。在渤海海峡“北进南出”的海流形态影响下，渤海海峡处的渤海水龄由南至北逐渐减小。无返回时，河流水、降水、外海水和渤海水在渤海中的水龄明显减小，但是对其在渤海中浓度和水龄的空间分布特征则没有多大变化。潮、风是影响渤海水龄分布的主要因素，温盐跃层对渤海水龄的影响较小。潮的存在能够使渤海水龄的增加程度可达55%以上，并且能够改变渤海水龄的垂向平均分布形态；风的存在能够使渤海水龄的减小程度达30%以上，但对渤海水龄的垂向平均分布形态影响很小；温盐跃层的存在也能够使渤海水龄有略微减小的趋势，仅在莱州湾东岸有使水龄增大的趋势，对渤海水龄的垂向平均分布形态的影响微弱。为了分析渤海各点源与面源间相互作用对渤海水龄的影响，以海河为中心考虑黄河、辽河和滦河点源对其水龄的影响，以河流水和降水为中心考虑河流点源对降水、外海水面源水龄的影响以及降水面源对河流水点源、外海水面源水龄的影响。黄河、滦河和辽河河流径流量的存在使海河水在渤海中的浓度和水龄减小约16%和12%；河流水的存在可使渤海水水龄减小约22%，使降水和外海水在渤海中的水龄减小约19%和18%；降水的存在可使渤海水龄减小约11%，使河流水和外海水在渤海中的水龄减小约14%和7%。因此，进一步说明了多水源区域对其多源水龄研究的必要性。
[Abstract]:As an auxiliary variable to understand the relationship between water dynamic process and physical chemistry or biological process of water body, water age plays an important role in the transport process and exchange process of matter in water body. For a particular water area, the source of the water body is often not single, so it is necessary to study the "multi-source" water age in the water area, but there is little research on it at present. In this paper, taking the Bohai Sea as an example, based on the three-dimensional Princeton ocean model (POM) simulation of the Bohai Sea hydrodynamic field, using the CART (the Constituent-orientedAge andthe Residence time Theory) theory to simulate the Bohai Sea water age, quantitative analysis of the Bohai Sea multi-source (river water), Through the selection of the open boundary conditions in the Bohai Sea, the influence of the return process on the water age in the Bohai Sea is discussed. Through a series of numerical experiments, the main dynamic mechanism of controlling the "multi-source" water age in the Bohai Sea and the influence of the interaction between the water sources on the water age are analyzed. Bohai Sea water is a multi-source water body composed of all sources of water (river water, precipitation, and outer sea water) in the Bohai Sea. Among them, river water, outer sea water and precipitation account for 12.28%, 77.24% and 10.48% of the total volume of the Bohai Sea respectively. The average water age was 1271 days, 1969 days and 1269 days, respectively. The volume of Bohai water in the Bohai Sea is 1810 days. With the increase of distance from the Bohai Strait, the water age of the Bohai Sea gradually increases. Under the influence of Bohai circulation, there are obvious seasonal variations in the spatial distribution of water age in the Bohai Sea, especially near the estuary region. With the emergence of seasonal leaps, the vertical distribution of the Bohai Sea water age also appears a certain layer, and the closer to the estuary, the more obvious the vertical stratification of the Bohai Sea water age. Under the influence of the current pattern of "North in and out of the Bohai Strait", the age of the Bohai Sea water in the Bohai Strait decreases gradually from the south to the north. When there is no return, the water age of river water, precipitation, outer sea water and Bohai sea water in the Bohai Sea decreases obviously, but the spatial distribution characteristics of its concentration and water age in the Bohai Sea do not change much. Tide and wind are the main factors affecting the distribution of water age in the Bohai Sea, and the temperature-salt leaps have little effect on the water age in the Bohai Sea. The presence of tide can increase the water age of the Bohai Sea by more than 55%, and can change the vertical average distribution of the water age of the Bohai Sea. The presence of wind can decrease the water age of Bohai Sea by more than 30%, but has little effect on the vertical average distribution of Bohai Sea water age. The presence of thermohalogen can also slightly decrease the water age in the Bohai Sea, but only on the eastern coast of the Laizhou Bay, and the vertical average distribution pattern of the water age in the Bohai Sea is slightly affected by the presence of the thermohalocline. In order to analyze the influence of interaction between point sources and non-point sources on the water age of Bohai Sea, the influence of point sources of the Yellow River, Liaohe and Luanhe rivers on their water ages is considered with Haihe River as the center, and the river water and precipitation as the center to consider the effect of river point sources on precipitation. The effects of surface water age and precipitation non-point source on river water point source and open sea surface source water age. The runoff of Yellow River, Luanhe River and Liaohe River decreased the concentration and age of Haihe River in Bohai Sea by about 16% and 12%. The presence of river water can reduce the water age of Bohai Sea by about 22%, and the water age of precipitation and outer sea water in Bohai Sea by about 19% and 18%. The presence of precipitation can reduce the water age of Bohai Sea by about 11%, and the water age of river water and outer sea water in Bohai Sea by 14% and 7% respectively. Therefore, it is necessary to study the multi-source water age in multi-source area.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P731

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