黄海冷水团年际变化研究

IOCAS-IR > 海洋环流与波动重点实验室

	黄海冷水团年际变化研究
	李昂1,2
学位类型	博士
导师	于非
	2016-05-18
学位授予单位	中国科学院大学
学位授予地点	北京
学位专业	物理海洋学
关键词	黄海冷水团年际变化影响因素敏感性试验
摘要	本文主要利用国家标准断面温、盐调查数据以及韩国海洋数据中心温、盐数据，分析了黄海冷水团温、盐的年际变化特征，结合多种气候资料分析了黄海冷水团的多种影响因素，最后利用数值模式敏感性实验研究了冬季风的动力效应对黄海冷水团不同核心温度影响，主要结论如下：（1）北黄海冷水团温度及其北部锋面存在明显的年际变化特征，北黄海冷水团中心最低温度具有升温趋势，北部锋面强度具有减弱趋势。冬季海温，气温，辐射通量以及经向风速都对北黄海冷水团的温度存在影响，东亚冬季风的年际变异是影响北黄海冷水团温度年际变化的重要机制，ENSO循环通过与东亚冬季风的相互作用与北黄海冷水团温度产生联系。（2）北黄海冷水团盐度中心存在轻微下降趋势, 盐度锋面与盐跃层表现出减弱的趋势，说明北黄海冷水团盐度与周围水团差异变小。黄海暖流入侵，北黄海区域蒸发降水通量，冬季风强度都是北黄海冷水团的重要影响因素。（3）南黄海冷水团两个核心的温度长期趋势不同，西部核心温度升高，东部核心温度降低。南黄海冷水团西部核心受到冬季黄海暖流入侵、冬季气温以及冬季经向风的影响。东部核心的降温趋势主要受到夏季过程的影响。黄海冷水团东部核心区域夏季所获暖水减少以及温跃层增强分别抑制了冷水团东部核心的水平以及垂直热输送，二者共同造成了东部核心的降温趋势。其中暖水入侵对的减弱可能由南黄海冷水团环流减弱所造成，温跃层增强主要受到海表温度升高以及深层热输送减少的影响。（4）南黄海冷水团盐度存在下降的长期趋势。南黄海冷水团盐度受到冬季黄海暖流高盐水入侵、黄海暖流源区盐度、蒸发降水通量以及长江流量的影响。济州岛西南海域盐度降低的趋势说明黄海暖流源区盐度下降，导致南黄海冷水团盐度下降。西北太平洋表层水的淡化趋势是入侵黄海高盐水淡化的原因。淡水通量首先影响表层盐度，通过冬季强混合以及环流作用影响到黄海冷水团区域。月平均蒸发降水信号和长江径流信号与南黄海冷水团第一主成分存在6个月左右的的滞后相关。（5）强（弱）冬季风作用下，较大（小）的黄海南北部海表面高度差，驱动出较强（弱）黄海暖流，使得北黄海及南黄海东部区域升（降）温，导致夏季北黄海冷水团及南黄海冷水团东部核心区域升（降）温，强（弱）冬季风驱动的强（弱）黄海西侧沿岸流使南黄海西部温度降低（升高），导致南黄海冷水团西部核心温度降低（升高）。
其他摘要	The interannual variability of the Yellow Sea Cold Water Mass is analysed based on the datasets of the China national standard section and Korea Oceanographic Data Center.The factors affecting the interannual variability of Yellow Sea Cold Water Mass are also studied. The dynamic effects of winter monsoon to the temperature of YSCWM are studied by using the sensitivity experiments. The main results showed that: （1）The temperature and the northern front of Northern Yellow Sea Cold Water Mass both have obvious interannual variation characteristics. The lowest temperature of the Northern Yellow Sea Cold Water Mass has a warming trend, and the northern front exist a weakening trend. The sea temperature, air temperature, meridional wind speed and radiation flux in winter has certain influence on the temperature of the NYSCWM. The influence of interannual variation of East Asian winter monsoon is a main mechanism of the interannual temperature variability of the northern Yellow Sea Cold Water Mass. By the interaction with East Asian winter monsoon, ENSO associated with northern Yellow Sea Cold Water Mass. （2）The mean salinity of the NYSCWM center has a slightly decreasing trend. The salinity front and the halocline of the NYSCWM display a weakening trend, which showed that the difference between the NYSCWM and the coastal water decreased. The Yellow Sea Warm Current intrusion, the E-P flux in winter, and the strength of the winter monsoon will affect the NYSCWM salinity. （3）The mean temperature of two centers of the SYSCWM had different long-term trends. The west center’s temperature of the SYSCWM was rising, while the east center’s temperature was falling. The mean temperature of the west center of the SYSCWM was related to the intrusion of the Yellow Sea Warm Current, the meridional wind speed and the air temperature in winter. Summer process played a primary role in the cooling trend of the east center’s temperature.The weakened warm water intrusion into the east center of SYSCWM in summer and stronger thermocline inhibits the horizontal and vertical heat transport, relatively. They commonly made the decreasing trend of the temperature. The weaker warm water intrusion might be caused by the weakened circulation of the SYSCWM. The higher surface temperature and less heat input in the deep layers intensified the thermocline of the east half of the SYSCWM. （4）The mean salinity of the center of the SYSCWM had a decreasing long-term trend. The mean salinity of the center of the SYSCWM was related to the saline water intrusion of the Yellow Sea Warm Current, the salinity of the source area of the YSWC, the evaporation minus precipitation (E-P) flux, and the discharge of the Changjiang River. The decreasing salinity trend to the southwest of Cheju Island led to the freshening trend in the YSWC, which caused the salinity of the SYSCWM to decrease. The freshening trends of the water from the northwest Pacific and Taiwan Strait could be seen as the reason for the decreasing salinity trend of the intrusion of water into the YS. The freshwater flux influenced the surface salinity and was brought to the deep layers by the circulation and the strong mixing in winter. The mean E-P flux signal and Changjiang River discharge signal lagged the first principal component of the SYSCWM for approximately 6 months. （5）Under the situation of the strong (weak) winter monsoon, big (small) sea surface height difference between the southern area and northern area of the YS drives strong (weak) YSWC. The strong (weak) YSWC makes high (low) temperature of the northern YS and the east area of the southern YS which will make higher (lower) temperature of NYSCWM and the east center of the SYSCWM. In the meantime, strong (weak) winter monsoon drives strong (weak) coastal current which makes the temperature of the west area of southern YS decrease. Then the west center of the SYSCWM temperature will decrease (increase).
学科领域	地球科学 ; 海洋科学 ; 物理海洋学
语种	英语
文献类型	学位论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/116966
专题	海洋环流与波动重点实验室海洋环境工程技术研究发展中心
作者单位	1.中国科学院海洋研究所 2.中国科学院大学
第一作者单位	中国科学院海洋研究所
推荐引用方式 GB/T 7714	李昂. 黄海冷水团年际变化研究[D]. 北京. 中国科学院大学,2016.

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