Corals Reveal Interdecadal Variation of Tropical Cyclones Modulated by Pacific Decadal Oscillation

Tropical cyclones (TCs) lead to huge economic losses and casualties in coastal regions, but multi-decadal variation of TC remains poorly understood due to the limited length of observational records and low-resolution reconstructions. Porites corals provide continuous and monthly resolved records that allow for the determination of weather-timescale (weekly to monthly) extreme events, including TC, to overcome the above limitations. Here we synthesize five coral Delta delta 18O records from the South China Sea (SCS) and develop a coral TC frequency index, in good agreement with post-1980 instrumental records and sediment-based TC reconstructions over the past century. Our results indicate that TC frequency in the SCS exhibits pronounced decadal variations, with active TCs corresponding to the negative phase of the Pacific Decadal Oscillation. Our findings here provide novel evidence for past TC changes in the SCS and a constraint for predicting future TC changes. The impact of tropical cyclones (TCs) on coastal regions results in significant economic losses and casualties. Due to the relatively short observations or low-resolution records, assessing long-term changes of TCs has suffered from large uncertainties. Porites corals are sensitive to environmental changes and can provide century-long, monthly resolved records, which could serve as a potential archive for reconstructing past TCs. Here we present five coral Delta delta 18O records from the South China Sea (SCS) and develop two TC frequency indexes. Both the TCs generated in the SCS and those entering the SCS from the Western North Pacific are reflected in our coral-based TCs reconstruction. In addition, our reconstruction suggests that the TCs in the SCS were increased in 1878-1888, 1894-1904, 1934-1952, 1971-1978, and 1995-2004, which corresponded to the negative phase of the Pacific Decadal Oscillation over the past century. Our findings provide new evidence for historical changes in TCs in the SCS and a valuable constraint for predicting future TC variations. The low residual oxygen isotope values of coral strongly respond to tropical cyclones in the South China Sea Excluding temperature, we reconstruct tropical cyclone activities in the South China Sea over the past century using coral oxygen isotopes Pacific Decadal Oscillation modulates tropical cyclones in the South China Sea over the past century