Nonlinear response of Northern Hemisphere stratospheric polar vortex to the Indo-Pacific warm pool (IPWP) Nino
Nonlinear response of Northern Hemisphere stratospheric polar vortex to the Indo-Pacific warm pool (IPWP) Nino
复制标题
北半球平流层极地涡旋对印度太平洋暖池（IPWP）尼诺的非线性响应
DOI：
10.1038/s41598-019-49449-7
复制
发表时间：
2019
影响因子：
4.6
通讯作者：
Cheng Zhigang
中科院分区：
文献类型：
--
作者：
Zhou Xin;Chen Quanliang;Xie Fei;Li Jianping;Li Minggang;Ding Ruiqiang;Li Yanjie;Xia Xin;Cheng Zhigang
热带海洋表面温度(SST)的变化对平流层极涡有显著的影响，厄尔尼诺现象的作用一直是研究的热点。然而，作为世界上最温暖的海水，印度-太平洋暖池(IPWP)却没有受到太多关注。最近几年，IPWP一直在变暖。本文首次报道了北半球冬季平流层环流和温度对IPWP增温(IPWP Niño)的显着非线性响应。在中等强度的IPWP尼诺过程中，NH涡旋减弱的强度较强且显著，而在IPWP强度较强的情况下，则减弱幅度较小且不显著。这一现象在历史模拟和观测中都是稳健的。在IPWP区域用线性变化的SST强迫进行的理想化模式实验分离了IPWP尼诺强度引起的非线性。在强IPWP尼诺事件期间，降水向西延伸到海洋大陆，推动了温带外波的衰减和西移。线性波干扰分析表明，这导致气候驻波和异常驻波之间的弱干扰，从而导致平流层涡旋的弱响应。这些发现暗示了平流层涡旋对IPWP尼诺现象的明显响应，并对NH地区的地表气候提供了更广泛的影响。
Variations in tropical sea surface temperatures (SST) have pronounced impacts on the stratospheric polar vortex, with the role of El Niño being the focus of much research interest. However, the Indo–Pacific warm pool (IPWP), which is the warmest body of seawater in the world, has received less attention. The IPWP has been warming in recent years. This paper presents for the first time the remarkable nonlinearity in Northern Hemisphere (NH) stratospheric circulation and temperature response to IPWP warming (the so-called IPWP Niño) in boreal winter. The magnitude of NH stratospheric vortex weakening is strong and significant in case of moderate IPWP Niño, but is weak and insignificant in strong IPWP Niño case. This phenomenon is robust in both the historical simulations and observations. An idealized model experiments forced with linear varying SST forcing in the IPWP region isolate the nonlinearities arising from IPWP Niño strength. Westward extension of precipitation into the Maritime Continent drives attenuation and westward shift of extratropical waves during strong IPWP Niño events. Linear wave interference analysis reveals this leads to weak interference between the climatological and anomalous stationary waves and thereby a weak response of the stratospheric vortex. These findings imply a distinct stratospheric vortex response to the IPWP Niño, and provide extended implications for the surface climate in the NH.