Sudden stratospheric warming (SSW) events often lead to a cold surface air temperature anomaly over the extratropical regions. In this study, we propose, through observational evidence, that the types of SSW determine the severity of the cold anomaly. Based on the three-type classification of SSW, it is found that the surface air temperature drops notably over central to eastern North America following an SSW-type transition, especially from displacement to split. Note, however, that the differences in mean surface air temperature anomalies between SSW types are not statistically significant, even though after SSW-type transition from displacement to split, surface air temperature anomalies are colder than the other two types. The development of an anomalous tropospheric ridge in the North Pacific Arctic sector, associated with the difference in the vertical and zonal propagation of planetary waves, characterizes the post-warming period of the displacement–split type. After the occurrence of the displacement–split type transition of SSW events, upward propagation of planetary waves of zonal wavenumber 1 is suppressed, whereas planetary waves of zonal wavenumber 2 increase in the troposphere. Accompanying the ridge in the North Pacific, a trough developed downstream over North America that carries cold polar air therein. The results in this study are relevant for the subseasonal time scale, within 20 days after an SSW occurrence.

突然的平流层变暖（SSW）事件通常导致温带地区上空的地表温度异常。在这项研究中，我们通过观察证据提出，SSW的类型决定了冷异常的严重程度。基于SSW的三类分类，发现在SSW型过渡之后，特别是从位移到分叉，地表温度在北美中部到东部东部明显下降。但是，请注意，即使在SSW类型从位移过渡到分裂后，SSW类型之间的平均表面气温异常的差异在统计上也不显着，尽管其他两种类型的表面温度异常较冷。北太平洋北极地区对流层异常脊的发展，与行星波的垂直传播和纬向传播的差异相关的特征是位移分裂型的变暖期。在发生SSW事件的位移-分裂型过渡之后，对流层1号地带波的行星波的向上传播受到抑制，而对流层2号地带波的行星波则增加。伴随着北太平洋的山脊，在北美下游形成了一个槽，在槽中携带着冷的极地空气。这项研究的结果与SSW发生后20天内的亚季节时间尺度有关。地层波数为1的行星波的向上传播受到抑制，而对流层数为2的地域波的行星波则增加。伴随着北太平洋的山脊，在北美下游形成了一个槽，在槽中携带着冷的极地空气。这项研究的结果与SSW发生后20天内的亚季节时间尺度有关。地层波数为1的行星波的向上传播受到抑制，而对流层数为2的地层波的行星波则增加了。伴随着北太平洋的山脊，在北美下游形成了一个槽，在槽中携带着冷的极地空气。这项研究的结果与SSW发生后20天内的亚季节时间尺度有关。