The South American rainfall dipole: A complex network analysis of extreme events
The South American rainfall dipole: A complex network analysis of extreme events
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DOI：
10.1002/2014gl061829
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发表时间：
2014-10-28
影响因子：
5.2
通讯作者：
Kurths, Juergen
中科院分区：
文献类型：
--
作者：
Boers, Niklas;Rheinwalt, Aljoscha;Kurths, Juergen
南美季风系统的季节内降水变率的特点是在南美东南部和巴西东南部之间有一个明显的偶极子。在这里，我们通过将非线性同步度量与复杂网络相结合来分析与此偶极子相关的极端降雨事件的动力学特性。我们的主要观察结果如下：(I)我们的方法揭示了两个偶极子位相极端事件的主要同步路径，(Ii)热带极端降水同步直接由信风及其安第斯山脉的偏转驱动，而副热带极端降水的传播主要由锋面系统决定，以及(Iii)众所周知的降雨偶极子实际上只是整个大陆振荡模式中最显著的模式。这进一步证明了Rossby波的影响延伸到赤道以外。Rossby波导致南美洲上空的锋面系统并影响大尺度环流模式。
Intraseasonal rainfall variability of the South American monsoon system is characterized by a pronounced dipole between southeastern South America and southeastern Brazil. Here we analyze the dynamical properties of extreme rainfall events associated with this dipole by combining a nonlinear synchronization measure with complex networks. We make the following main observations: (i) Our approach reveals the dominant synchronization pathways of extreme events for the two dipole phases, (ii) while extreme rainfall synchronization in the tropics is directly driven by the trade winds and their deflection by the Andes mountains, extreme rainfall propagation in the subtropics is mainly dictated by frontal systems, and (iii) the well-known rainfall dipole is, in fact, only the most prominent mode of an oscillatory pattern that extends over the entire continent. This provides further evidence that the influence of Rossby waves, which cause frontal systems over South America and impact large-scale circulation patterns, extends beyond the equator.