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 troposphere of mid-latitudes which, sometimes, terminate in Rossby Wave Breaking (RWB) events. If RWB events reach certain spatial and temporal scale, they are considered to be synoptically identical to atmospheric blockings, which are linked to heatwaves and droughts. Thus, understanding RWB events linked to RWPs propagation and their link with atmospheric blocking development is key to enhance extreme weather events detection 10-30 days in advance. Hence, in this study we assess the occurrence of RWB events after the propagation of short-lived RWPs (RWPs with a lifespan below or equal to 8 days, or SLRWPs) or long-lived RWPs (RWPs with a lifespan above 8 days, or LLRWPs), whether SLRWPs or LLRWPs are linked to large-scale RWB events that could form an atmospheric blocking event, and, lastly, study the proportion of blocking situations that occur near RWB events. To do so, we applied a tracking algorithm to detect RWPs in the Southern Hemisphere during summertime between 1979-2020, developed a wave breaking algorithm to identify and follow RWB events, and searched for atmospheric blocking events with different intensities. Results show that LLRWPs and SLRWPs displayed large-scale RWB events around 40% of the time, which tend to last around 1-2 days, which is not sufficient to identify them as blocking situations. Nearly 17% of blockings show a RWB event nearby whenever they manifest, but barely 5% of blockings are linked to RWB caused by RWPs propagation, therefore, propagating RWPs do not seem to be strongly linked to atmopsheric blocking development. Lastly, the occurrence of large-scale RWB events associated with SLRWPs are influenced by El Niño-Southern Oscillation and the Southern Annular Mode.