2026-10-06T11:06:23Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34053876 2026-10-02T04:40:26Z category_62 portal_316 item_type_3 month_year_10_2026

Data Sheet 1_Extreme compound events in the Agulhas Leakage.pdf Mariana V. A. Zorzo (25161885) Regina R. Rodrigues (8076986) Camila Artana (22886504) Marine Biology detrending long-term change marine heatwaves ocean acidification extremes South Atlantic Ocean <p>Marine heatwaves (MHWs) and ocean acidity extremes (OAXs) are intensifying under anthropogenic climate change, and their compound co-occurrence can amplify ecological impacts. Yet the Agulhas Leakage, a key gateway transferring warm, saline Indian Ocean water into the Atlantic, remains understudied. Here we characterise MHWs over 1982–2024 and OAXs, and their compound events in this region over 1982–2021, comparing analyses of original and linearly detrended data. Under a fixed baseline, MHW cumulative intensity rose from approximately 29.95 to 109.51 °C-year in the original data and 49.4 to 66.7 °C-year after detrending between the first and fourth decades. OAX intensity increased from approximately 0.24 to 4.10 nmol kg^-¹-year in the original data and from 0.35 to 0.46 nmol kg^-¹-year after detrending. Compound events emerge only after the 2000s. Detrending reveals that most of this increase reflects the long-term warming and acidification trends, while residual variability remains in the dynamically active Agulhas Retroflexion, where anticyclonic eddies trap warm, high [H⁺] Indian Ocean waters. A likelihood multiplication factor confirms statistically significant positive MHW–OAX dependence that persists after detrending, indicating statistically significant positive co-occurrence between MHW and OAX on interannual timescales, consistent with physical coupling through carbonate chemistry. Baseline choice critically shapes compound-extreme risk assessment.</p> 2026-10-02T04:40:26Z Dataset Dataset 10.3389/fmars.2026.1949899.s001 https://figshare.com/articles/dataset/Data_Sheet_1_Extreme_compound_events_in_the_Agulhas_Leakage_pdf/34053876 CC BY 4.0