钱代丽,管兆勇. 2018. 超强与普通厄尔尼诺海-气特征差异及对西太平洋副热带高压的不同影响[J]. 气象学报, 76(3):394-407, doi:10.11676/qxxb2018.011
超强与普通厄尔尼诺海-气特征差异及对西太平洋副热带高压的不同影响
Different features of super and regular El Niño events and their impacts on the variation of the West Pacific Subtropical High
投稿时间:2017-09-05  修订日期:2017-12-25
DOI:10.11676/qxxb2018.011
中文关键词:  厄尔尼诺  海洋次表层  西太平洋副热带高压  开尔文波  Gill型响应
英文关键词:El Niño  Subsurface ocean  West Pacific Subtropical High  Kelvin wave  Gill-type response
基金项目:国家自然科学基金重点资助项目(41330425)、公益性行业(气象)科研专项(GYHY201406024)、江苏省高校优势学科建设工程资助项目(PAPD)。
作者单位E-mail
钱代丽 南京信息工程大学气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心/气候与环境变化国际合作联合实验 室, 南京, 210044  
管兆勇 南京信息工程大学气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心/气候与环境变化国际合作联合实验 室, 南京, 210044 guanzy@nuist.edu.cn 
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中文摘要:
      利用NCEP/NCAR再分析资料、GODAS海洋资料、哈得来中心海表温度(SST)以及中国国家气候中心(NCC)环流指数数据,依据美国气候预测中心的厄尔尼诺事件标准筛选出1980-2016年的超强与普通厄尔尼诺事件,对比了两类事件的不同生命阶段内海表及次表层温度特征的差异,并探讨了其对西太平洋副热带高压(西太副高)的不同影响。结果表明,对超强厄尔尼诺事件而言,海表温度正距平发展早且迅速,其大值中心偏东,纬向梯度强,但对普通厄尔尼诺事件而言,海表温度正距平中心偏西,纬向梯度小。厄尔尼诺事件的发展源于次表层海温距平(SOTA)随开尔文波东传并沿温跃层上升到达海表,其波动前部区域异常垂直海流对次表层海温距平的变化起重要作用;当海气激烈耦合时,可在温跃层激发出更强的海洋波动,使得次表层变暖更明显,激发出强的厄尔尼诺事件。海温异常强迫出的大气异常环流的强度与强迫源的强度关系密切。两类厄尔尼诺均能通过异常的沃克环流引起大气Gill型响应,使得西太副高偏强、西伸,且当超强厄尔尼诺发生时,异常沃克环流更强,海洋性大陆区域上空的异常强辐散导致Gill型响应而产生的反气旋更强,对西太副高的影响更甚。印度洋海表温度对厄尔尼诺的滞后变暖所带来的影响在上述亚太大气环流的持续异常中起重要作用。这些结果有利于加深对不同类型厄尔尼诺事件及影响西太副高机理的认识。
英文摘要:
      Using the NCEP/NCAR reanalysis, the GODAS ocean data and the Hadley sea surface temperature (SST) and National Climate Center (NCC) circulation indices data, the super and regular El Niño events are investigated with focus on the features of sea surface and subsurface layers as well as their possible impacts on the West Pacific Subtropical High (WPSH). It is demonstrated that for super El Niño events, positive sea surface temperature anomalies (SSTA) appear relatively earlier and develop faster with a stronger zonal gradient of SSTA. The maximum of positive SSTA is located in Nino3 region. However, for regular El Niño events, positive SSTA are located more westward and the zonal gradient of SSTA is weaker. During the El Niño episodes, the subsurface ocean temperature anomalies (SOTA) propagate eastward with Kelvin waves and reach up to the sea surface along the thermocline. The vertical currents in front of Kelvin waves play an important role in the change of SOTA. Stronger oceanic waves can be excited in the thermocline when air-sea couples more intensively, which are favorable for higher SOTA and thus possibly induce a super El Niño event. In both types of El Niño events, abnormal anticyclonic circulations are generated over the western Pacific and South China Sea due to the Gill-type responses. As the intensity of the anomalous atmospheric circulation forced by SSTA is closely related to the intensity of forcing sources, the WPSH is stronger in super El Niño cases than in regular ones. Besides, the lagged warming of SST in the Indian Ocean in response to El Niño is favorable for the persistence of atmospheric circulation anomalies in the Asian-Pacific region. These results are helpful for better understanding the features of different types of El Niño events and their impacts on the WPSH.
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