Step Increase in Eastern U.S. Precipitation Linked to Indian Ocean Warming
Step Increase in Eastern U.S. Precipitation Linked to Indian Ocean Warming
复制标题
DOI：
10.1029/2020gl088911
复制
发表时间：
2020-08
影响因子：
5.2
通讯作者：
C. Strong;G. McCabe;Alexander Weech
中科院分区：
文献类型：
--
作者：
C. Strong;G. McCabe;Alexander Weech
20 世纪 70 年代初，美国东部年降水量逐步增加，开启了长达 50 年的水文气候活跃期，对水流和水资源产生了持续影响。尽管影响深远，但这种变化的动力起源尚不清楚。这里对一个世纪的大气和海洋数据的分析追踪了印度洋变化的动态。秋季降水量的增加对阶跃增加的贡献最大，相关机制是由变暖的印度洋上空的深层对流产生的泛太平洋大气波的出现。今年秋季遥相关的记录引起人们对热带海洋热含量预计人为增加及其对中纬度地区水文气候的潜在影响的关注。
A step increase in annual precipitation over the eastern United States in the early 1970s commenced five decades of invigorated hydroclimate, with ongoing impacts on streamflow and water resources. Despite its far‐reaching impacts, the dynamical origin of this change is unknown. Here analyses of a century of atmospheric and oceanic data trace the dynamics to changes in the Indian Ocean. Increases in fall precipitation contribute most strongly to the step increase, and the associated mechanism is emergence of a pan‐Pacific atmospheric wave emanating from deep convection over the warming Indian Ocean. Documentation of this fall teleconnection draws attention to projected anthropogenic increases in tropical oceanic heat content and their potential impacts on hydroclimate of the midlatitudes.