Influence of the May Southern annular mode on the South China Sea summer monsoon
Influence of the May Southern annular mode on the South China Sea summer monsoon
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5月南环模态对南海夏季风的影响
DOI：
10.1007/s00382-017-3753-3
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发表时间：
2018-12-01
期刊：
影响因子：
4.6
通讯作者：
Yao, Zhixiong
中科院分区：
文献类型：
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作者：
Liu, Ting;Li, Jianping;Yao, Zhixiong
研究了五月南半球（SH）环形模式（SAM）对接下来的南中国海（SCS）夏季风（SCSSM）的可能影响。观察结果显示两者之间存在密切的反比关系。同时南太平洋偶极子（SPD）是南太平洋的一种类似偶极子的海面温度异常模式，它充当“海洋桥梁”来保存5月的SAM信号并将其延长到6月至9月。观测证据和数值模拟都表明，SPD 向大气传达了巨大的热惯性信号，调节了澳大利亚东部上空的南太平洋副热带急流 (SPSJ) 的变化。与SPSJ相关的环流调整相对应的是一个突出的三极跨太平洋遥相关格局，从SH中高纬度延伸到NH东亚沿海地区，称为南北太平洋（SNP）遥相关格局。波浪射线追踪分析表明，SNP充当“大气桥梁”，将相关波浪能穿过赤道传播到海洋大陆和南海季风区，调节垂直运动和中下部对流层气流，有利于南海夏季风的异相变化。因此，“海-气耦合桥”过程及相关的罗斯贝波能传输是5月南半球环状模对后续南海夏季风变化产生重大影响的可能机制。因此，5月南半球环状模从南半球高纬度地区的角度对南海夏季风的预测提供了新的视角。
The possible impact of the May Southern Hemisphere (SH) annular mode (SAM) on the following South China Sea (SCS) summer monsoon (SCSSM) is examined. A close inverse relationship between the two is revealed in the observations. The simultaneous South Pacific dipole (SPD), a dipole-like sea surface temperature anomaly pattern in the South Pacific, acts as the “oceanic bridge” to preserve the May SAM signal and prolong it into June–September. Observational evidence and numerical simulations both demonstrate that the SPD communicates its large thermal inertia signal to the atmosphere, regulating the Southern Pacific Subtropical Jet (SPSJ) variability over eastern Australia. Corresponding to the adjustment of circulation associated with the SPSJ is a prominent tripolar cross-Pacific teleconnection pattern stretching from the SH middle–high latitudes into the NH East Asia coastal region, referred to as the South–North Pacific (SNP) teleconnection pattern. Wave ray tracing analysis manifests that the SNP acts as the “atmospheric bridge” to propagate the related wave energy across the equator and into the Maritime Continent and SCS monsoon region, modulating the vertical motion and middle–lower tropospheric flows, and favoring the out-of-phase variation of the SCSSM. Therefore, the “coupled oceanic-atmospheric bridge” process and the related Rossby wave energy transmission are possible mechanisms for the significant influence of the May SAM on the variability of the following SCSSM. Therefore, the May SAM provides a fresh insight into the prediction of the SCSSM from the perspective of the SH high latitudes.