Influences of climate change on tropical cyclones: An insight into the Western North Pacific over the past two millennia

Understanding the variation of tropical cyclones (TCs) and climate in the Western North Pacific (WNP) over the past two millennia can help us understand how TCs might change with the global warming scenario. Instrumental observations and model projections have revealed that the characteristics of TCs in the WNP are related to climate forcing. However, the limited availability of short instrumental records impedes our comprehension of the interactions between TCs and climate on historical time scales. Reconstructing the TC activity on geological time requires reliable alternative proxies, including sediments, tree rings, stalagmites, corals, Tridacna shells, and historical documents. This review mainly summarizes the reconstructions of paleo-TCs over the past two millennia and discusses the characteristics of TCs during typical climatic periods. Reconstructions of TC activity have indicated significant spatial and temporal asynchrony across the low to mid-latitudes in the WNP during the past two millennia. Our compilation includes 10 different sites in the WNP and further ascertains the range of the transition zone (24.74 degrees similar to 25.87 degrees N). The TC frequency north (south) of the transition zone and SST were positively (negatively) correlated over the past two millennia. This pattern suggests that SST dominates the variation of TCs north of the transition zone and other pieces of evidence indicate that TCs south of the transition zone are controlled by Intertropical Convergence Zone. Notedly, El Nino-Southern Oscillation, aerosol, and the latitudinal shift of TCs also contribute to this pattern. Future research on paleo-TC and paleoclimate over the past two millennia should focus on improving the accuracy of proxies, increasing the resolution of proxy-based records, and expanding the representative areas to reconstruct comprehensive paleo-TC archives. This can provide powerful support for the study of TC variation patterns and climatic forcing mechanisms on decadal to centennial timescales, and contribute to the prediction of TC activity during the current warm period.