Confronting Contemporary Seasonality Changes in East Asian Tropical Cyclone Landfalls with a Multi-Century Historical Baseline

TL;DR

This study uses a multi-century historical baseline to analyze recent changes in East Asian tropical cyclone landfalls, finding that observed shifts are within natural variability and challenging to attribute to human influence.

Contribution

It introduces a multi-source framework combining historical and modern data to assess seasonality changes in tropical cyclone landfalls over centuries.

Findings

Contemporary landfall timing shift is within historical natural variability.

Natural controls on TC timing are consistent across eras.

Pre-industrial datasets are validated for climate studies.

Abstract

Paleoclimate records provide a critical long-term perspective on natural climate variability, essential for understanding contemporary climate change. However, existing paleoclimate proxies lack the spatial-temporal coverage for studying changes in high-impact weather extremes like tropical cyclones (TCs). Here we introduce a multi-source framework that confronts the contemporary changes in TC landfalls in East Asia with a multi-century baseline (1368-1911) reconstructed from historical documents. Leveraging pre-industrial and contemporary data, the analysis reveals that a relatively small shift toward earlier landfalls in the contemporary era (1946-2020). However, this shift falls well within the range of natural fluctuations documented historically (1651-1900). This low signal-to-noise ratio indicates the forced anthropogenic signal of TC landfall timing remains challenging to detect. Besides providing a template for assessing seasonality changes in extremes, our work shows consistent natural controls of TC timing in contemporary and pre-industrial eras, lending credibility to pre-industrial observational datasets and climate simulations.