大风和海洋涡旋对中国近海冬季水交换的影响研究

发布时间：2018-04-27 19:18

本文选题：冬季大风 + 谱聚类　；参考：《上海海洋大学》2016年硕士论文

【摘要】：不同海域之间进行的水体交换能够促进海洋物质的交换,有利于稀释海洋污染物的浓度,对海洋环境的自净作用具有重要意义。基于ROMS海洋数值模式,本文对中国近海海洋动力环境进行模拟,通过引用优化的谱混合模型方法对渤黄海之间的水交换问题进行研究分析。在此基础上,分析了一次大风过程对渤黄海水交换的影响,以及黑潮两侧涡旋对东海和黑潮之间水交换的影响。1、渤黄海水交换区的定义和特征利用ROMS海洋数值模式对2006年冬季渤黄海海域的海洋动力环境进行模拟,基于温度和盐度的模拟结果,采用优化后的的谱混合模型方法进行水团分析,确定出渤黄海之间的水交换区。研究发现,冬季,在渤黄海地区分布着低温渤海水团和高温黄海水团,并且黄海水团呈“舌”形分布于渤海海峡北部地区。两海域之间的水交换区则表现为沿“舌”形边缘呈带状分布,具有西北——东南的走向趋势,位于“舌”尖处的水交换区面积最大,而且黄海最北部的沿岸海域并不参与渤黄海之间的水体交换。2、冬季大风对渤黄海水交换的影响根据冬季渤黄海海域风速随时间的变化趋势情况,选取一次大风事件(2007年2月14日),并以此次大风事件为例,探讨大风事件对渤黄海水交换区的影响。研究发现,冬季大风事件对渤黄海之间的水体交换具有促进作用,具体表现为:大风过程使黄海暖流对渤海的入侵更加深入,水交换区向渤海方向伸展,南部的水交换区变宽,黄河径流进入渤海后与渤海水的混合区加大,并发生北移。大风过后两天内,渤海海峡地区的水交换区向黄海方向退缩,同时,莱州湾地区的混合区也向沿岸方向退去。3、1991-2006年冬季东海大陆架200米水体积通量异常情况基于roms海洋数值模式对1991-2006年东海海洋动力环境的模拟资料,本文对1991-2006年期间冬季东海大陆架200米水体积通量异常与流场之间的关系进行分析。研究发现,1997、2003和2004三年的水体积通量表现为异常高值,其中1997年的水体积通量达到历史最高值。同时,东海陆架水与黑潮之间的水交换较弱,台湾东部一段黑潮向远离东海陆架的方向偏移;2000、2002和2005三年的水体积通量表现为异常低值,其中2000年的水体积通量达到历史最低值。同时,东海陆架水与黑潮之间的水体交换较强,黑潮在台湾东北部的入侵更深。4、1997年和2000年东海涡旋的移动特征通过分别分析两个特殊年份1997年和2000年冬季200米水体积通量的异常情况与相应东海涡旋的运动情况,发现:1997年冬季200米水体积通量达到历史最高值,黑潮以西的气旋涡由东海沿西南方向移向黑潮,黑潮与东海之间水交换区的面积减小,水交换减弱;2000年冬季200米水体积通量达到历史最低值,台湾东北部的气旋式冷涡不明显,黑潮以西的气旋涡由黑潮沿西北方向移向东海沿岸,黑潮与东海之间水交换区的面积增大,水交换能力加强。另外,研究发现,东海涡旋的产生与ENSO有一定的联系。5、涡旋对东海和黑潮之间水交换的影响基于全球海洋中尺度涡旋的分析结果资料,本文对东海涡旋进行了辨认和动态追踪,对其时空变化规律进行了统计分析,讨论了冬季东海涡旋的时空分布与东海陆架200米水体积通量的关系。研究发现,黑潮主轴向东海方向的弯曲附近是涡旋的频发地,当东海涡旋分布在琉球群岛西北从黑潮主轴中间段以西到济州岛以南一带时,有利于东海与黑潮之间的水交换。另外,黑潮主轴以西由黑潮沿西北方向移向东海陆架的涡旋,能够减弱东海大陆架200米等深线断面的水体积通量,促进东海与黑潮之间的水交换过程。通过统计涡旋个数发现,东海地区的总涡旋数越多,尤其是气旋涡个数越多,越有利于东海与黑潮之间的水交换过程。
[Abstract]:Water exchange between different sea areas can promote the exchange of marine materials, help to dilute the concentration of marine pollutants, and be of great significance to the self purification of the marine environment. Based on the ROMS ocean numerical model, this paper simulates the marine dynamic environment of China's offshore sea, and through the method of cite optimized spectral mixture model to the Bohai the Yellow Sea On the basis of this, the influence of a large wind process on the exchange of Bohai Sea water and the influence of the two vortices on the water exchange between the East China Sea and the Kuroshio.1, the definition and characteristics of the Bohai Sea water exchange area in the Bohai the Yellow Sea sea area in the winter of 2006 are analyzed. The environment is simulated, based on the simulation results of temperature and salinity, the water mass analysis is carried out by the optimized method of spectral mixing model. The water exchange area between Bohai and the Yellow Sea is determined. In the winter, the low temperature Bohai water mass and the high temperature the Yellow Sea water mass are distributed in the Bohai the Yellow Sea region, and the Yellow Sea Water regiment is distributed in the "tongue" form in the Bohai Strait. In the northern area, the water exchange area between the two sea areas shows a zonal distribution along the edge of the "tongue" shape, with the trend of north-west and Southeast, the largest water exchange area at the tip of the tongue, and the coastal waters in the northern part of the Yellow Sea do not participate in the water exchange between Bohai and the Yellow Sea, and the winter winds exchange the sea water to the Bohai Sea. According to the change trend of wind speed with time in the Bohai the Yellow Sea sea area in winter, a large wind event (February 14, 2007) is selected, and the wind event is taken as an example to discuss the influence of the wind event on the Bohai Sea water exchange area. The wind process makes the the Yellow Sea warm current invade Bohai more deeply, the water exchange area extends to the Bohai direction, the water exchange area in the south is broadened, the the Yellow River runoff enters Bohai and the mixing area of Bohai water increases and moves north. In the two days after the wind, the water exchange area of the Bohai Straits shrink from the direction of the Yellow Sea, while the Laizhou Bay area is mixed. The area also receded to the coastal direction of the 200 m water volume flux anomaly in the East China Sea continental shelf in winter.31991-2006, based on the simulation data of the ROMs ocean numerical model on the marine dynamic environment of the East China Sea for 1991-2006 years. The relationship between the 200 m water volume flux anomaly and the flow field in the East China Sea shelf in the winter of 1991-2006 years was analyzed. It is found that the water flux in the 19972003 and the 2004 three years shows an abnormal high value, of which the water volume flux in 1997 reaches the highest historical value. At the same time, the water exchange between the East China Sea shelf water and the Kuroshio is weak, and the east part of the East Taiwan Kuroshio moves away from the East China Sea shelf, and the water flux in the 20002002 and 2005 three years is very low. The water volume flux in 2000 has reached a historical minimum. At the same time, the water exchange between the East China Sea shelf water and the Kuroshio is stronger. The characteristics of the dark tide in the northeast of Taiwan and the movement of the East China Sea in 2000 are analyzed by analyzing the abnormal conditions of the 200 m water volume flux in the two special years in 1997 and 2000 respectively. With the movement of the corresponding vortex in the East China Sea, it is found that the 200 meter water volume flux reached the highest value in winter in 1997. The gas vortex from the west of the Kuroshio moved from the East China Sea to the Kuroshio in the southwest. The area of the water exchange area between the Kuroshio and the East China Sea decreased and the water exchange weakened. In the winter of 2000, the water volume flux of 200 meters reached the historical minimum, and the northeast of Taiwan. The cyclone vortex is not obvious, and the cyclonic vortex west of the Kuroshio moves from the Kuroshio to the East China Sea along the northwest direction. The area of the water exchange area between the Kuroshio and the East China Sea increases and the water exchange capacity is strengthened. In addition, it has been found that the formation of the vortex in the East China Sea has a certain connection with the ENSO.5, and the effect of the vortex on the water exchange between the East China Sea and the Kuroshio is based on the global sea. The data of the analysis of the oceanic mesoscale vortices in the East China Sea have been identified and dynamically traced, and the temporal and spatial variation of the East China Sea is analyzed. The relationship between the spatial and temporal distribution of the East China Sea and the 200 meter water volume of the East China Sea shelf in the East China Sea is discussed. When the East China Sea vortex is distributed in the northwest of the Ryukyu Islands from the middle of the main shaft of the Kuroshio to the south of Jeju Island, it is beneficial to the exchange of water between the East China Sea and the Kuroshio. In addition, the vortex of the main axis of the Kuroshio from the West of the Kuroshio to the East China Sea shelf from the Kuroshio to the East China Sea can weaken the water volume flux of the 200 m ISO section of the East China Sea. The process of water exchange between the East China Sea and the Kuroshio. Through the number of statistical vortices, it is found that the more the total vortex number in the East China Sea, the more the number of cyclones, the more conducive to the water exchange between the East China Sea and the Kuroshio.

【学位授予单位】：上海海洋大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：P731.2

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