The North Atlantic Oscillation and the Arctic Oscillation are modes of climate variability affecting temperature and precipitation in the mid-latitudes. Here we use reanalysis data and climate model simulations of historical and warm climates to show that the relationship between the two oscillations changes with climate warming. The two modes are currently highly correlated, as both are strongly influenced by the downward propagation of stratospheric polar vortex anomalies into the troposphere. When considering a very warm climate scenario, the hemispherically defined Arctic Oscillation pattern shifts to reflect variability of the North Pacific storm track, while the regionally defined North Atlantic Oscillation pattern remains stable. The stratosphere remains an important precursor for North Atlantic Oscillation, and surface Eurasian and Aleutian pressure anomalies precede stratospheric anomalies. Idealized general circulation model simulations suggest that these modifications are linked to the stronger warming of the Pacific compared with the slower warming of the Atlantic Ocean.

北大西洋涛动和北极涛动是影响中纬度地区温度和降水的气候变率模式。在这里，我们使用历史和温暖气候的再分析数据和气候模型模拟来表明两种振荡之间的关系随着气候变暖而变化。这两种模式目前高度相关，因为它们都受到平流层极涡异常向下传播到对流层的强烈影响。在考虑非常温暖的气候情景时，半球定义的北极涛动模式会发生变化，以反映北太平洋风暴轨迹的变化，而区域定义的北大西洋涛动模式保持稳定。平流层仍然是北大西洋涛动的重要前兆，和地表欧亚和阿留申压力异常先于平流层异常。理想化的大气环流模型模拟表明，与大西洋变暖较慢相比，这些修改与太平洋变暖的加剧有关。