研究人员使用观测数据和最先进的气候模型发现，在过去的40年里，EUS冬季AR频率显著增加(约10% dec-1)。这一趋势与太平洋/北美(PNA)遥相关型最近的变化密切相关，并伴随着中纬度急流向极地移动。研究进一步揭示了AR发生的年际变化和PNA指数之间的强相关性(R=0.8；P＜0.01)。这种联系已在各种模型模拟中得到验证。
建立在这种联系基础上的统计模型已被证明，其可以有效地在月度和季度尺度上使用PNA指数预测AR频率。研究人员强调，这些有希望的结果对解决该地区与AR相关的极端降水和洪水有关的问题具有重要意义。
据研究人员介绍，大气层河流(ARs)在美国各地的各种极端天气事件中扮演着重要的角色。虽然美国西部的大气层河流特征已得到广泛的研究，但对其在美国东部(EUS)的可变性的了解仍然有限。
附：英文原文
Title: Atmospheric rivers over eastern US affected by Pacific/North America pattern
Author: Wenhao Dong, Ming Zhao, Zhihong Tan, V. Ramaswamy
Issue&Volume: 2024-01-26
Abstract: Atmospheric rivers (ARs) play important roles in various extreme weather events across the US. While AR features in western US have been extensively studied, there remains limited understanding of their variability in the eastern US (EUS). Using both observations and a state-of-the-art climate model, we find a significant increase (~10% dec-1) in winter AR frequency in the EUS during the past four decades. This trend is closely linked to recent changes in the Pacific/North America (PNA) teleconnection pattern, accompanied by a poleward shift of the mid-latitude jet stream. We further reveal a strong correlation (R = 0.8; P < 0.001) between interannual variations in AR occurrence and the PNA index. This linkage has been verified in various model simulations. A statistical model, built on this linkage, has proven effective in predicting the AR frequency using the PNA index at both monthly and seasonal scales. These promising results have important implications for addressing concerns related to AR-associated extreme precipitation and flooding in this region.
DOI: adj3325
Source: https://www.science.org/doi/10.1126/sciadv.adj3325