Atmospheric rivers (ARs) are narrow regions of intense water vapour transport in the Earth’s atmosphere. These transient phenomena carry water from the subtropics to the mid-latitudes and polar regions^1,2, making up the majority of polewards moisture transport^3,4,5 and exerting control on the precipitation and water resources in many regions^6,7. In addition to transporting moisture, ARs also transport heat, but the impact of this transport on global near-surface air temperatures has not yet been characterized. Here we show that seasons with more frequent ARs also have warmer than average temperatures in many mid-latitude regions, and that AR events are associated with temperature anomalies of 5–10 °C above the climatological mean. This is due to anomalous horizontal transport and convergence of sensible heat and moisture in the lower atmosphere, which increases both downward sensible heat flux and downwelling long-wave radiation at the surface. On an hourly timescale, over 70% of extreme warm-temperature anomalies occur within ARs in large portions of the mid-latitudes, and ARs are associated with moist and compound heatwaves in many regions worldwide, suggesting that consideration of ARs may improve predictive capability for certain extreme heat events. Our results demonstrate that ARs significantly impact air temperatures on a wide array of timescales, and that they may play a wider role in global energy transport than previously recognized.

大气河流 （AR） 是地球大气中强烈水蒸气输送的狭窄区域。这些瞬态现象将水从亚热带带到中纬度和极地地区^{1,2，构成了}极地水分输送的大部分^3,4,5，并控制了许多地区的降水和水资源^6,7。除了输送水分外，AR 还输送热量，但这种输送对全球近地表气温的影响尚未确定。在这里，我们表明，在许多中纬度地区，AR 更频繁的季节温度也高于平均水平，并且 AR 事件与高于气候平均值 5-10 °C 的温度异常有关。这是由于低层大气中显热和湿气的异常水平传输和汇聚，这增加了表面向下的显热通量和长波辐射。在每小时的时间尺度上，超过 70% 的极端暖温异常发生在中纬度地区大部分地区的 AR 内，并且 AR 与全球许多地区的潮湿和复合热浪有关，这表明考虑 AR 可能会提高对某些极端高温事件的预测能力。我们的结果表明，AR 在广泛的时间尺度上显着影响气温，并且它们在全球能源运输中可能发挥比以前认识到的更广泛的作用。