Parallel comparison of the 1982/83, 1997/98 and 2015/16 super El Nios and their effects on the extratropical stratosphere
Parallel comparison of the 1982/83, 1997/98 and 2015/16 super El Nios and their effects on the extratropical stratosphere
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1982/83年、1997/98年和2015/16年超级厄尔尼诺斯现象的平行比较及其对温带平流层的影响
DOI：
10.1007/s00376-017-6260-x
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发表时间：
2017
影响因子：
5.8
通讯作者：
Ren Rongcai
中科院分区：
文献类型：
--
作者：
Rao Jian;Ren Rongcai
本研究使用多个海面温度（SST）数据集对三个超级厄尔尼诺现象及其对平流层的影响进行平行比较。结果表明，与普通厄尔尼诺现象不同，暖海温异常最早出现在热带西太平洋，且比超级厄尔尼诺峰值早18个月以上。去年冬天，相对于厄尔尼诺现象的成熟期，作为前兆，观察到了类北太平洋涛动的环流异常。尽管太平洋-北美（PNA）波瓣的强度和纬向位置之间存在细微差异，但在成熟阶段，温带对流层中仍出现了太平洋-北美（PNA）遥相关。与热带印度洋上空的负降雨响应有关，1997/98冬季的PNA遥相关是三个超级厄尔尼诺现象中最强的。如果从环流数据中线性滤除其他因素的干扰，北方冬季平流层的极冠温度和环极西风会出现较大的异常。与超级厄尔尼诺冬季的PNA正响应相关，在三个超级厄尔尼诺的成熟冬季也观察到极冠温度异常和环极东风异常，尽管时间不同。明年冬季的平流层极地涡旋相对于1982/83年和1997/98年的事件也异常减弱和温暖，随着2015/16年事件的成熟阶段，平流层环流条件有待观察。
This study uses multiple sea surface temperature (SST) datasets to perform a parallel comparison of three super El Niños and their effects on the stratosphere. The results show that, different from ordinary El Niños, warm SST anomalies appear earliest in the western tropical Pacific and precede the super El Niño peak by more than 18 months. In the previous winter, relative to the mature phase of El Niño, as a precursor, North Pacific Oscillation-like circulation anomalies are observed. A Pacific–North America (PNA) teleconnection appears in the extratropical troposphere during the mature phase, in spite of the subtle differences between the intensities, as well as the zonal position, of the PNA lobes. Related to the negative rainfall response over the tropical Indian Ocean, the PNA teleconnection in the winter of 1997/98 is the strongest among the three super El Niños. The northern winter stratosphere shows large anomalies in the polar cap temperature and the circumpolar westerly, if the interferences from other factors are linearly filtered from the circulation data. Associated with the positive PNA response in a super El Niño winter, positive polar cap temperature anomalies and circumpolar easterly anomalies, though different in timing, are also observed in the mature winters of the three super El Niños. The stratospheric polar vortex in the next winter relative to the 1982/83 and 1997/98 events is also anomalously weaker and warmer, and the stratospheric circulation conditions remain to be seen in the coming winter following the mature phase of the 2015/16 event.