Distribution and trend of explosive cyclones over the Southern Ocean and associated atmospheric and oceanic changes during 1980–2020

• Published in: Geoscience letters Vol. 11; no. 1; pp. 38 - 13
• Main Authors: Xu, Xiaoqi, Liu, Jiping, Huang, Gang, Ding, Yifan
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2024; Springer Nature B.V; SpringerOpen
• Subjects: Anomalies; Atmospheric Sciences; Autumn; Biogeosciences; Climatology; Cyclones; Deepening rate; Earth and Environmental Science; Earth Sciences; Explosive cyclones; Geophysics/Geodesy; Heat flux; Heat transfer; Ice cover; Latent heat; Long wave radiation; Oceanography; Planetology; Research Letter; Sea ice; Sea surface temperature; Temperature anomalies; The Southern Ocean; Wind effects; Winds; Pacific Ocean; Southern Ocean; The Southern Ocean; Explosive cyclones; Sea surface temperature; Deepening rate
• ISSN: 2196-4092
• DOI: 10.1186/s40562-024-00356-4

In this study, we investigate the climatology and trend of explosive cyclones (ECs) over the Southern Ocean (50 o S–70 o S) during 1980–2020 by combining a method that is most suited for identifying and tracking cyclones in the Southern Ocean and a latest climate reanalysis. On average, approximately 50 ECs are generated annually over the Southern Ocean, with a significant increasing trend of 2.3 per decade during the studying period. This increasing trend is dominated by the trend of strong ECs, particularly in autumn. We analyze the dynamical and thermodynamical effects associated with multiple deepened strong ECs in autumn over an identified key region in the southern Pacific Ocean sector (155 o W–170 o W, 50 o S–65 o S), where the density of the initiation of ECs shows the largest increasing trend in autumn. The composite analysis reveals the general patterns and duration of the effects on the atmosphere, ocean, and sea ice associated with multiple ECs in the southern Pacific Ocean. The results indicate that the deepened strong ECs are associated with significant changes in meridional winds, downward longwave radiation, and sensible and latent heat fluxes. These changes lead to cold sea surface temperature anomalies in the northeast of the key region, reaching a maximum 5–7 days after the EC deepening, and the increased sea ice cover south of the key region, peaking 4–5 days after the EC deepening. Highlights Explosive cyclones (ECs) over the Southern Ocean (50 o S–70 o S) have a significant increasing trend of 2.3 per decade during 1980–2020. The increasing trend is dominated by the trend of strong ECs, especially in autumn. The anomalies of sea surface temperature and sea ice cover can sustain about 2 weeks following the generation of strong ECs.