北太平洋副热带模态水潜沉率变异规律及其机制研究

发布时间：2018-04-20 19:30

本文选题：副热带模态水 + 潜沉率　；参考：《中国科学院研究生院(海洋研究所)》2016年博士论文

【摘要】：北太平洋副热带模态水是冬末海气相互作用产生的垂向性质均一的低位涡水,可以将气候变化的异常信号通过潜沉的作用进入永久性密度跃层,并且向低纬度海域输运,对低纬度海域的气候异常有重要影响。因此,认识和了解北太平洋副热带模态水潜沉的变异规律和变异机制,有助于进一步掌握北太平洋副热带和热带之间的相互作用,是海洋与大气相互作用研究的热点问题之一。目前对于潜沉率的研究大多是依赖于对模式数据的分析,利用观测数据对潜沉率年际、年代际变异和变异机制的研究较为稀少,然而,Argo数据从2001年持续至今,随着Argo观测网络的日渐完善,已经可以提供十年以上的有效数据支持大尺度海洋过程的研究。本文利用2003-2013年逐月Argo观测数据和1960-2010年SODA数据,对北太平洋副热带西部模态水(the Subtropical Mode Water, STMW),东部模态水(the Eastern Subtropical Mode Water,ESTMW),以及中部模态水(the Central Mode Water,CMW)潜沉率的变异规律和变异机制进行了系统的分析,并且得到了一些创新性的研究成果。首先,根据北太平洋副热带模态水STMW、ESTMW和CMW的潜沉区进行划分,选择28°-35°N,140°E-180°作为STMW的潜沉区,360-45°N,145°E-160°W为CMW潜沉区,200-28°N,150°W-120°W为ESTMW潜沉区。潜沉区的潜沉率平均时间序列以及EOF分析的空间分布都显示,STMW、ESTMW和CMW的潜沉率异常主要是来自侧向输运项异常的贡献,体现了混合层深度异常对潜沉率异常的作用。通过控制晚冬温度和盐度的气候态或者逐年的变化,北太平洋模态水潜沉区内的晚冬混合层深度进行控制变量分析显示,在STMW和ESTMW潜沉区内,晚冬混合层温度异常是混合层深度异常的主要因素,盐度异常并不会带来混合层深度的显著变化,而在CMW潜沉区内,晚冬混合层盐度异常表现出了和温度异常相当的作用。副热带模态水潜沉区的晚冬热收支及CMW潜沉区的晚冬盐度收支分析结果中,STMW和CMW潜沉区内,晚冬混合层热收支变异与平流项变异和热通量项都存在显著正相关的关系,Argo数据显示在2003-2013年间,热收支的增强趋势主要收到了来自平流项增强趋势的贡献。ESTMW潜沉区内,夹卷项与热收支相关性显著,并且2003-2013年间只有夹卷项与热收支项都存在减弱的趋势。盐度收支的结果也体现了平流作用在CMW潜沉区的重要作用。SODA数据结果在模态水潜沉率年际变异规律和变异机制上都表现出了与Argo数据结果的一致性,结合1960-2009年SODA和2003-2013年Argo潜沉率结果进行年代际变异规律进行研究,1970s气候突变前后,STMW、ESTMW和CMW潜沉率都存在明显的突变,而随着1980s后一段时间PDO指数变异趋势的减弱,模态水潜沉率也保持着平缓的变化,直到2000年后PDO位相发生转变,STMW和CMW产生了较强的减弱趋势,而ESTMW也表现出了加强的趋势,因此,2000年后可能存在气候突变的新节点,并且副热带模态水潜沉率的变异也开始响应了这一突变。
[Abstract]:The subtropical modal water in the North Pacific is a low horizontal vortex water produced by the interaction of sea air interaction in the late winter. It can enter the anomalous signal of climate change into the perpetual density layer through submersible action and transport to the low latitude sea area, which has an important influence on the climate abnormality in the low latitude sea area. Therefore, the North Pacific is recognized and understood. The variation and variation mechanism of Subtropical Mode water submersible will help to further understand the interaction between the subtropics and the tropics in the North Pacific. It is one of the hot issues in the study of ocean and atmosphere interaction. The study of Interdecadal Variability and variation mechanisms is scarce. However, Argo data has been continued since 2001. With the gradual improvement of the Argo observation network, more than ten years of effective data can be provided to support large scale marine processes. This paper uses the monthly 2003-2013 year Argo observation data and 1960-2010 year SODA data to the North Pacific. The modal water (the Subtropical Mode Water, STMW), the eastern modal water (the Eastern Subtropical Mode Water, ESTMW), and the variation and variation mechanism of the middle modal water (the), are systematically analyzed and some innovative research results are obtained. First, according to North Taiping. The subtropical zone of Subtropical Mode water, STMW, ESTMW and CMW, is divided into 28 degrees -35 N, 140 degree E-180 degrees as the submersible area of STMW, 360-45 degree N, 145 degree E-160 W as CMW submersible area, 200-28 degree N, 150 degrees as submersible area. The rate anomaly mainly comes from the contribution of the lateral transport anomaly, reflecting the effect of the mixed layer depth anomaly on the anomaly of the submersible rate. By controlling the climate state of late winter temperature and salinity or year by year, the control variable analysis of the late winter mixed layer depth in the North Pacific modal water submersible area shows that it is late in the STMW and ESTMW submersible areas. The temperature anomaly in the mixed layer is the main factor of the depth anomaly of the mixed layer, and the salinity anomaly does not bring about a significant change in the depth of the mixed layer. In the CMW submersible area, the late winter mixture salinity anomaly shows the same effect as the temperature anomaly. The late winter heat budget of the subtropical zone and the late winter salinity of the CMW submersible area In the STMW and CMW submersible areas, there is a significant positive correlation between the heat budget variation in the late winter mixed layer and the advection variation and the heat flux. The Argo data show that during the 2003-2013 period, the trend of the increase of heat budget is mainly in the.ESTMW submersible area, which is from the advection term enhancement, and the correlation of the entrainment item and the heat budget is significant. In the past 2003-2013 years, only the reel and the heat budget have a weakening trend, and the results of the salinity budget also reflect the important role of the advection in the CMW submersible area. The results of.SODA data in the interannual variation and variation mechanism of the modal water submersible rate are consistent with the results of the Argo data, combined with 1960-2009 years of SODA and 20. The interdecadal variation of Argo submersible rate in 03-2013 was studied. Before and after the 1970s climate mutation, there was a significant mutation in the STMW, ESTMW and CMW submersible rates. With the decrease of the PDO index variation trend in the later period of 1980s, the mode water submersible rate also maintained a gentle change until the PDO phase changed after the 2000, STMW and CMW. There was a strong weakening trend, and the ESTMW showed a tendency to strengthen. Therefore, there might be a new node in the climate change after 2000, and the variation of Subtropical Mode water submersible rate began to respond to this mutation.

【学位授予单位】：中国科学院研究生院(海洋研究所)
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P732.6;P731

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