Wave breaking events and their Link to Rossby wave packets and atmospheric blockings during Southern Hemisphere Summer

Rossby Wave Packets (RWPs) are atmospheric perturbations located at the upper levels in mid‐latitudes which, under certain circumstances, terminate in Rossby Wave Breaking (RWB) events. When RWB events are sufficiently persistent and spatially extended, they are synoptically identical to atmospheric blockings, which are linked to heatwaves and droughts. Therefore, studying RWB events that occur after RWPs propagation and their link with blocking is key to enhance extreme weather events detection between 10–30 days in advance. In this study we assessed the occurrence of RWB events after the propagation of transient RWPs, whether long‐lived RWPs (RWPs with a lifespan > 8 days, or LLRWPs) are linked to large‐scale RWB events that could form a blocking event, and the proportion of blocking situations that occur near large-scale RWB events. To do so, we applied a tracking algorithm to detect and follow transient RWPs in the southern hemisphere during summertime between 1979-2021, developed a wave breaking algorithm to identify RWB events, and searched for blocking events with different intensities. Results show that LLRWPs and the other RWPs displayed large‐scale RWB events around 40% of the time, and most of the RWB events in both distributions last around 1–2 days, which is not long enough to identify them as blocking situations. Nearly 17% of blockings showed a RWB event nearby, but barely 5% of these blockings were linked to RWPs, thus suggesting that transient RWPs are not strongly linked to blocking development. Lastly, large‐scale RWB events associated with RWPs that lasted less than 8 days are influenced by El Niño‐Southern Oscillation