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Prehistoric Intense Tropical Cyclones in the South Pacific Ocean.

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Název: Prehistoric Intense Tropical Cyclones in the South Pacific Ocean.
Autoři: Li, Yanan1,2 (AUTHOR) yananli.nju@gmail.com, Donnelly, Jeffrey P.2 (AUTHOR), Gao, Shu1 (AUTHOR) shugao@nju.edu.cn, Gao, Jianhua1 (AUTHOR), Bramante, James F.2 (AUTHOR), d'Entremont, Nicole2 (AUTHOR), Kotra, Krishna K.3 (AUTHOR)
Zdroj: Geophysical Research Letters. 9/16/2025, Vol. 52 Issue 17, p1-12. 12p.
Témata: *TROPICAL cyclones, *PALEOCLIMATOLOGY, *COASTAL zone management, *ISLANDS, *SEDIMENT analysis, *EXTREME weather, EL Nino
Geografický termín: FIJI, SOUTH Pacific Ocean
Abstrakt: Tropical cyclones in relation to global warming pose an increasing threat to coastal populations and property, highlighting an urgent need for millennial‐scale paleoclimate reconstructions. In this study, we reconstruct an 8500‐year record of tropical cyclone activity, based on sediment cores from a coastal lake in Fiji. Using coarse fraction anomalies (>63 μm) as the primary proxy, 58 intense cyclones have been identified, revealing multi‐centennial periods with enhanced and reduced cyclone activities. Consistent cyclone occurrences are observed across different sites in the South Pacific during the Roman Warm Period, Medieval Climate Anomaly, and Little Ice Age, all coinciding with pronounced El Niño‐ or La Niña‐like conditions, while a zonal seesaw pattern emerges during neutral to moderate ENSO phases. We propose that variations in the position and structure of the South Pacific Convergence Zone modulated by various ENSO phases offer an accurate indicator of long‐term cyclone variability, superior to ENSO indices alone. Plain Language Summary: Tropical cyclones are among the most destructive natural hazards affecting coastal regions. However, our understanding of their long‐term changes in intensity and frequency of occurrence is limited because the instrumental meterological records are too short; long‐term paleoclimatic data are needed. In this study, we present an 8500‐year record of intense tropical cyclones in the central South Pacific, based on sediment core analysis from Salt Lake on Vanua Levu Island, Fiji. We identified 58 coarse‐grained layers indicative of cyclone events, revealing alternating multi‐centennial periods of quiescence and activation. Comparison with other sedimentary records over the region demonstrates consistent patterns of cyclone occurrence during the Roman Warm Period, Medieval Climate Anomaly and Little Ice Age. These patterns are due to the variations in the position and structure of the South Pacific Convergence Zone, in addition to the ENSO indices. Key Points: Sedimentary record of intense tropical cyclone activity over the past eight millenniums from a coastal lake of FijiCoherent intense cyclone occurrence among sites in the South Pacific during Roman Warm Period, Medieval Climate Anomaly and Little Ice AgeSouth Pacific Convergence Zone position and structure variations as superior indicators of long‐term cyclone activity to ENSO indices [ABSTRACT FROM AUTHOR]
Databáze: Academic Search Index
Popis
Abstrakt:Tropical cyclones in relation to global warming pose an increasing threat to coastal populations and property, highlighting an urgent need for millennial‐scale paleoclimate reconstructions. In this study, we reconstruct an 8500‐year record of tropical cyclone activity, based on sediment cores from a coastal lake in Fiji. Using coarse fraction anomalies (>63 μm) as the primary proxy, 58 intense cyclones have been identified, revealing multi‐centennial periods with enhanced and reduced cyclone activities. Consistent cyclone occurrences are observed across different sites in the South Pacific during the Roman Warm Period, Medieval Climate Anomaly, and Little Ice Age, all coinciding with pronounced El Niño‐ or La Niña‐like conditions, while a zonal seesaw pattern emerges during neutral to moderate ENSO phases. We propose that variations in the position and structure of the South Pacific Convergence Zone modulated by various ENSO phases offer an accurate indicator of long‐term cyclone variability, superior to ENSO indices alone. Plain Language Summary: Tropical cyclones are among the most destructive natural hazards affecting coastal regions. However, our understanding of their long‐term changes in intensity and frequency of occurrence is limited because the instrumental meterological records are too short; long‐term paleoclimatic data are needed. In this study, we present an 8500‐year record of intense tropical cyclones in the central South Pacific, based on sediment core analysis from Salt Lake on Vanua Levu Island, Fiji. We identified 58 coarse‐grained layers indicative of cyclone events, revealing alternating multi‐centennial periods of quiescence and activation. Comparison with other sedimentary records over the region demonstrates consistent patterns of cyclone occurrence during the Roman Warm Period, Medieval Climate Anomaly and Little Ice Age. These patterns are due to the variations in the position and structure of the South Pacific Convergence Zone, in addition to the ENSO indices. Key Points: Sedimentary record of intense tropical cyclone activity over the past eight millenniums from a coastal lake of FijiCoherent intense cyclone occurrence among sites in the South Pacific during Roman Warm Period, Medieval Climate Anomaly and Little Ice AgeSouth Pacific Convergence Zone position and structure variations as superior indicators of long‐term cyclone activity to ENSO indices [ABSTRACT FROM AUTHOR]
ISSN:00948276
DOI:10.1029/2024GL113976