Atmospheric rivers (ARs) significantly impact the hydrological cycle and associated extremes in western continental regions. Recent studies suggest ARs also influence water resources and extremes in continental interiors. AR detection tools indicate that AR conditions are relatively frequent in areas east of the Rocky Mountains. The origin of these ARs, whether from synoptic-scale waves or mesoscale processes, is unclear. This study uses meteorological composite maps and transects of AR conditions during the four seasons. The analysis reveals that ARs east of the Rockies are associated with long-wave, baroclinic Rossby waves. This result demonstrates that eastern North American ARs are dynamically similar to their western coastal counterparts, though mechanisms for vertical moisture flux differ between the two. These findings provide a foundation for understanding future climate change and ARs in this region and offer new methods for evaluating climate model simulations.

中文翻译：

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美国东部和中西部的大气河流与斜压波有关

大气河流（AR）对西部大陆地区的水文循环和相关极端事件产生重大影响。最近的研究表明，AR 也会影响水资源和大陆内部的极端情况。 AR 检测工具表明，AR 情况在落基山脉以东地区相对频繁。这些 AR 的起源，无论是天气尺度波还是中尺度过程，尚不清楚。本研究使用四个季节的气象合成图和 AR 条件横断面。分析表明，落基山脉以东的 AR 与长波斜压罗斯贝波有关。这一结果表明，北美东部的 AR 与西海岸的 AR 动态相似，尽管两者的垂直水分通量机制不同。这些发现为了解该地区未来气候变化和 AR 奠定了基础，并为评估气候模型模拟提供了新方法。