Observational Evidence of Distinguishable Weather Patterns for Three Types of Sudden Stratospheric Warming During Northern Winter

Abstract

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.

Two Leading Modes in the Evolution of Major Sudden Stratospheric Warmings and Their Distinctive Surface Influence

“…Downward SSWs manifest as continuous downward propagation of the stratospheric anomalies and thus affecting the surface weather, whereas the lower-level impact of non-downward SSWs is weak. Depending on the wave amplitude evolution during the life cycle of the warming event, SSWs can be separated into displacement-displacement type, displacement-split type and split-split type (Choi et al, 2019(Choi et al, , 2021. Basing on the differences in the coupling process of the isentropic meridional mass circulation between the stratosphere and the troposphere, the negative stratospheric NAM events can also be categorized (Yu & Ren, 2019).…”

Stratospheric PULSE–continental cold air outbreak coupling relationships: Interannual and interdecadal changes

“…In particular, weak stratospheric polar vortex anomalies or negative Northern Annular Mode (NAM) or stratospheric sudden warming (SSW) events are favorable to colder surface air temperatures or a higher occurrence of CAOs in mid-latitude regions of Eurasian and North American continents during the following months (Thompson et al, 2002;Kenyon and Hegerl, 2008;Tomassini et al, 2012;Kidston et al, 2015;Lehtonen and Karpechko, 2016;Garfinkel et al, 2017;Karpechko, 2018). Particularly, the cold anomalies tend to occur over North America (Eurasia) 1−2 weeks after (before) a weak stratospheric polar vortex event or a displacement-type SSW event, whereas cold anomalies tend to occur over both continents in 1 month around the split-type SSW events (Mitchell et al, 2013;Kidston et al, 2015;Lehtonen and Karpechko, 2016;Yu et al, 2018a;Choi et al, 2019;Choi et al, 2021).…”

Coupling between maximum temperature and ozone levels in the lower stratosphere and extreme cooling events in Northeast China

“…The polar vortex perturbed by planetary waves produces a zonally asymmetric pattern in the SSW effects observed in air temperature, winds, total ozone content (TOC) and tropopause altitude (Thompson and Wallace 2000;Kolstad et al 2010;Kidston et al 2015;Kim and Kim 2021;Ding et al 2022). Because of quasi-stationary wave structure, the SSW influence is often manifested as a persistent extreme cold weather in certain regions, such as Northern Europe, northeastern North America or East Asia (Thompson and Wallace 2000;Tomassini et al 2012;Lehtonen and Karpechko 2016;Lü et al 2020;Butler et al 2020;Choi et al 2021;Rao et al 2021;Kolstad et al 2022;Zhang et al 2022;Liu et al 2023). We analyze regional extreme cooling events, which involve stratosphere-troposphere coupling but are not associated with the SSW.…”