Wang et al. (2025) Polarised Changes in Sub‐Daily Precipitation Extremes and Underlying Mechanisms Over Southwest China in a Warmer Climate

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: International Journal of Climatology
• Year: 2025
• Date: 2025-10-05
• Authors: Yujie Wang, Lianchun Song, Pengke Shen
• DOI: 10.1002/joc.70140

Research Groups

Not specified in the abstract.

Short Summary

This study statistically analyzed sub-daily precipitation extremes (SPEs) over Southwest China from 1971–2024, revealing simultaneous increases in both wet and dry SPEs driven by atmospheric circulation changes and thermodynamic factors in a warming climate.

Objective

• To statistically analyze spatiotemporal variations of sub-daily precipitation extremes (SPEs) over Southwest China and identify the underlying mechanisms driving their polarized changes (simultaneous increases in both wet and dry extremes).

Study Configuration

• Spatial Scale: Southwest China (SWC)
• Temporal Scale: Summers of 1971–2024

Methodology and Data

• Models used: Statistical analysis methods.
• Data sources: Observation data from 338 meteorological stations.

Main Results

• Sub-daily precipitation extremes (SPEs) exhibit simultaneous increases in both wet and dry extremes across Southwest China.
• The SPE risks for 20-year and 50-year return periods increased by 2–8 times and 4–17 times, respectively, in 2001–2024 compared to 1971–2000.
• Precipitation intensity at 1–3 hour intervals shows a more pronounced upward trend (3.4% per decade) than at 6–12 hour intervals (2.7% per decade).
• Wet SPEs show a nearly consistent upward trend across SWC, with larger magnitudes in Chongqing, southern Sichuan, and southern Yunnan.
• Remarkable increases in dry SPEs occur in Yunnan and southern Guizhou.
• Enhanced and westward-extended Western Pacific Subtropical High (WPSH), combined with enhanced and eastward-extended South Asian High (SAH), are key factors driving increased wet SPEs.
• Extraordinary westward extension of the WPSH is conducive to forming dry SPEs.
• In a warming climate, increases in saturated vapor pressure, specific humidity, water vapor convergence, and convective available potential energy are associated with substantial increases in wet SPEs.
• Simultaneously, increased saturated vapor pressure makes it more difficult for water vapor to reach saturation, triggering occurrences of dry SPEs.

Contributions

• Provides a scientific basis for decision-makers adapting to sub-daily precipitation extremes.
• Offers valuable insights for further in-depth research on polarized changes in precipitation extremes and their underlying mechanisms.
• Addresses a gap in understanding simultaneous increases in both wet and dry sub-daily precipitation extremes over Southwest China.

Funding

Not specified in the abstract.

Citation

@article{Wang2025Polarised,
  author = {Wang, Yujie and Song, Lianchun and Shen, Pengke},
  title = {Polarised Changes in Sub‐Daily Precipitation Extremes and Underlying Mechanisms Over Southwest China in a Warmer Climate},
  journal = {International Journal of Climatology},
  year = {2025},
  doi = {10.1002/joc.70140},
  url = {https://doi.org/10.1002/joc.70140}
}