In recent decades, both the frequency of intense typhoon and their destructive potential have increased. Understanding the mechanisms of such intensification is critical for assessing wind damage and secondary hazards induced by extreme ocean dynamics. Using the China Meteorological Administration (CMA) best-track dataset for 1979–2024, together with the Joint Typhoon Warning Center (JTWC) best-track record archived in the International Best Track Archive for Climate Stewardship (IBTrACS), this study examines changes in typhoon intensity from a standard deviation (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\sigma\)</EquationSource> </InlineEquation>) perspective, with trend inference conducted on annual series. Results indicate that intensification signals are more consistently expressed through changes in <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(\sigma\)</EquationSource> </InlineEquation> than through a shift in the mean. For maximum wind speed, the long-term mean exhibits no statistically significant trend for the overall region, while <InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\sigma\)</EquationSource> </InlineEquation> demonstrates a generally increasing tendency with pronounced subregional/nearshore expressions, indicating a shift toward greater extremes rather than a basin-wide mean shift, with <InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\sigma_{v}\)</EquationSource> </InlineEquation> becoming statistically significant in the IBTrACS–JTWC (1-min wind) sensitivity analysis. For minimum central pressure, the contrast is clearer: the mean shows no significant trend, whereas the standard deviation increases significantly for the overall region (+ 2.09 hPa dec−1, p = 0.02), providing direct evidence of a broadening intensity distribution. Consistent with this spread-driven interpretation, energy-scale diagnostics based on PDI (CMA only) and a driver-oriented decomposition indicate that long-term changes are not dominated by sampling volume or residence-time effects, but are more aligned with intensity-related contributions. Even in the absence of a mean shift, an increase in the <InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\sigma\)</EquationSource> </InlineEquation> implies a wider intensity distribution and a higher probability of extreme outcomes. These findings support a standard-deviation–driven interpretation of typhoon-extreme intensification near the South China coast, providing a process-based explanation for intensification and a quantitative basis for non-stationary extreme value analyses in hazard assessment and coastal engineering design.

Intensification of typhoon extremes along the South China coast: a standard deviation perspective

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发表日期：

2026年2月26日

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Feifan Fang,
Liangsheng Zhu,
Yao Luo

摘要

In recent decades, both the frequency of intense typhoon and their destructive potential have increased. Understanding the mechanisms of such intensification is critical for assessing wind damage and secondary hazards induced by extreme ocean dynamics. Using the China Meteorological Administration (CMA) best-track dataset for 1979–2024, together with the Joint Typhoon Warning Center (JTWC) best-track record archived in the International Best Track Archive for Climate Stewardship (IBTrACS), this study examines changes in typhoon intensity from a standard deviation ( \(\sigma\) ) perspective, with trend inference conducted on annual series. Results indicate that intensification signals are more consistently expressed through changes in \(\sigma\) than through a shift in the mean. For maximum wind speed, the long-term mean exhibits no statistically significant trend for the overall region, while \(\sigma\) demonstrates a generally increasing tendency with pronounced subregional/nearshore expressions, indicating a shift toward greater extremes rather than a basin-wide mean shift, with \(\sigma_{v}\) becoming statistically significant in the IBTrACS–JTWC (1-min wind) sensitivity analysis. For minimum central pressure, the contrast is clearer: the mean shows no significant trend, whereas the standard deviation increases significantly for the overall region (+ 2.09 hPa dec⁻¹, p = 0.02), providing direct evidence of a broadening intensity distribution. Consistent with this spread-driven interpretation, energy-scale diagnostics based on PDI (CMA only) and a driver-oriented decomposition indicate that long-term changes are not dominated by sampling volume or residence-time effects, but are more aligned with intensity-related contributions. Even in the absence of a mean shift, an increase in the \(\sigma\) implies a wider intensity distribution and a higher probability of extreme outcomes. These findings support a standard-deviation–driven interpretation of typhoon-extreme intensification near the South China coast, providing a process-based explanation for intensification and a quantitative basis for non-stationary extreme value analyses in hazard assessment and coastal engineering design.