Increased typhoon activity in the Pacific deep tropics driven by Little Ice Age circulation changes
Increased typhoon activity in the Pacific deep tropics driven by Little Ice Age circulation changes
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DOI：
10.1038/s41561-020-00656-2
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发表时间：
2020-11-16
影响因子：
18.3
通讯作者：
Donnelly, Jeffrey P.
中科院分区：
文献类型：
--
作者：
Bramante, James F.;Ford, Murray R.;Donnelly, Jeffrey P.
仪器记录表明，热带气旋活动对海洋和大气在年际和年代际尺度上的变化很敏感。然而，我们对气候对热带气旋行为的影响的了解受到历史记录较短和史前重建稀少的限制，特别是在西北太平洋地区，那里的沿海社区每年都因台风而丧失生命和生计。在这里，为了探索过去的区域台风动力学，我们重建了三千年来北太平洋热带深处的气旋发生。结合现有的记录，我们的重建表明，1350年前的低基线台风活动之后是小冰期期间频繁的风暴间隔。这种模式与水气候替代变异性同时存在，表明太平洋水气候和热带气旋气候学之间存在百年尺度的联系。一组全球气候模式表明，在小冰期，太平洋Walker环流和变率在两种太平洋气候模式中迁移，这可能是北太平洋热带西部热带气旋活动增强的原因。在下个世纪，预计太平洋沃克环流的变化和热带的扩张将逆转这些小冰期的水气候趋势，潜在地减少热带深层的台风活动。根据对过去风暴活动的沉积物代理记录和一般环流模式输出的比较，小冰期期间的大气环流变化导致热带北太平洋更大的台风生成。
The instrumental record reveals that tropical cyclone activity is sensitive to oceanic and atmospheric variability on inter-annual and decadal scales. However, our understanding of the influence of climate on tropical cyclone behaviour is restricted by the short historical record and the sparseness of prehistorical reconstructions, particularly in the western North Pacific, where coastal communities suffer loss of life and livelihood from typhoons annually. Here, to explore past regional typhoon dynamics, we reconstruct three millennia of deep tropical North Pacific cyclogenesis. Combined with existing records, our reconstruction demonstrates that low-baseline typhoon activity prior to 1350 ce was followed by an interval of frequent storms during the Little Ice Age. This pattern, concurrent with hydroclimate proxy variability, suggests a centennial-scale link between Pacific hydroclimate and tropical cyclone climatology. An ensemble of global climate models demonstrates a migration of the Pacific Walker circulation and variability in two Pacific climate modes during the Little Ice Age, which probably contributed to enhanced tropical cyclone activity in the tropical western North Pacific. In the next century, projected changes to the Pacific Walker circulation and expansion of the tropics will invert these Little Ice Age hydroclimate trends, potentially reducing typhoon activity in the deep tropical Pacific.Atmospheric circulation shifts during the Little Ice Age led to greater typhoon generation in the tropical North Pacific according to a comparison of sediment proxy records of past storm activity and outputs of general circulation models.