Yao et al. (2025) Increasing coupling of hot‒dry winds and drought across China: Observational evidence and future projection

Identification

• Journal: Advances in Climate Change Research
• Year: 2025
• Date: 2025-11-08
• Authors: Feng Yao, Fubao Sun, Hong Wang, Fa Liu
• DOI: 10.1016/j.accre.2025.10.011

Research Groups

• Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China
• College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, China

Short Summary

This study investigates the historical and future dynamics of compound hot-dry wind and drought events (CHDWDs) across China using observations and CMIP6 simulations. It reveals an increasing coupling and likelihood of CHDWDs, particularly in drylands, with future intensification projected under higher emission scenarios and varying dominant drivers across climatic zones.

Objective

• To characterize the historical spatiotemporal evolution of hot-dry winds (HDWs), droughts, and compound HDW and drought events (CHDWDs) across China from 1980 to 2022 using meteorological observations.
• To project future changes in HDWs, droughts, and CHDWDs under different Shared Socioeconomic Pathway (SSP) scenarios using Coupled Model Intercomparison Project Phase 6 (CMIP6) multi-model simulations.
• To quantify the contributions of individual HDW and drought events to CHDWD frequency and intensity.

Study Configuration

• Spatial Scale: National scale for China, with historical data at 0.25° × 0.25° resolution and future projections at 0.5° × 0.5° resolution.
• Temporal Scale:
  • Historical: 1980–2022 (43 years)
  • Future: 2025–2100 (76 years)
  • Temporal resolution: Daily data converted to monthly averages for index calculation.

Methodology and Data

• Models used:
  • Coupled Model Intercomparison Project Phase 6 (CMIP6)
  • Inter-Sectoral Impact Model Intercomparison Project Phase 3b (ISIMIP3b)
  • Five Global Climate Models (GCMs): GFDL-ESM4, IPSL-CM6A-LR, MPI-ESM1-2-HR, MRI-ESM2-0, UKESM1-0-LL.
  • Indices: Standardized Precipitation-Evapotranspiration Index (SPEI) for drought, Standardized Hot-Dry-Windy Index (SHDWI) for HDW, and Compound HDW and Drought Index (CHDWDI = SHDWI × SPEI) for CHDWDs.
  • Potential Evapotranspiration (PET) calculation: Penman-Monteith equation.
  • Statistical methods: Multiple Linear Regression (MLR) for contribution analysis, Sen’s slope estimator for trends, and Mann–Kendall statistical test for significance.
• Data sources:
  • Historical: 0.25° × 0.25° gridded daily meteorological dataset (temperature in degrees Celsius, relative humidity in percent, wind speed in meters per second, precipitation in millimeters) from 2416 meteorological stations across China, obtained from the China Meteorological Data Service Center (1980–2022).
  • Future: Daily climate simulations (average and maximum temperatures in Kelvin, precipitation in kilograms per square meter per second, relative humidity in percent, wind speed in meters per second) from five CMIP6 GCMs at 0.5° × 0.5° resolution, obtained from ISIMIP3b (2025–2100) under SSP1-2.6, SSP3-7.0, and SSP5-8.5 scenarios.

Main Results

• Historical (1980–2022):
  • HDW severity intensified across China, with SHDWI showing a significant downward trend of -0.05 per decade (p < 0.05). Hyper-arid (-0.075 per decade) and humid (-0.063 per decade) regions experienced the most pronounced intensification.
  • Drought conditions aggravated, with SPEI showing a significant downward trend of -0.07 per decade (p < 0.01). Drier regions (hyper-arid: -0.24 per decade; arid: -0.16 per decade; semi-arid: -0.12 per decade) showed the largest declines.
  • A strong positive correlation (r = 0.79, p < 0.01) was observed between HDW severity and drought conditions across China, strengthening in drier regions (e.g., r = 0.94 in hyper-arid regions).
  • The likelihood of CHDWDs significantly increased across China (CHDWDI trend of 0.093 per decade, p < 0.01), with drylands showing substantially stronger upward trends. CHDWD frequency increased by 0.39 months per decade (p < 0.01) and intensity by 0.09 per decade (p < 0.01).
  • Drought contributed more to CHDWD frequency (77%–91%) and intensity (55%–76%) in arid northern and western China, while HDW contributed more to CHDWD frequency (41%–46%) and intensity (57%–64%) in humid southern and eastern regions.
• Future Projections (2025–2100):
  • Under medium (SSP3-7.0) and high (SSP5-8.5) emission scenarios, both SPEI and SHDWI show declining trends, indicating worsening drought and HDW conditions, with more pronounced declines under SSP5-8.5.
  • CHDWDI shows a marked increase after 2075 under SSP3-7.0 and SSP5-8.5, indicating a late-century amplification of compound extreme events. CHDWD frequency is projected to be higher under SSP5-8.5 > SSP3-7.0 > SSP1-2.6.
  • For CHDWD frequency, drought dominates (68%–87%) under SSP1-2.6 and SSP3-7.0. However, under SSP5-8.5, HDW contributes more (54%) than drought in humid regions, while drought remains dominant (72%–97%) in non-humid regions.
  • For CHDWD intensity, HDW consistently contributes more (53%–71%) than drought in humid regions across all SSPs, whereas drought contributes more (54%–83%) in non-humid regions.

Contributions

• This study provides novel insights into the synergistic increasing pattern of HDWs and droughts across China, integrating both observational evidence and future projections.
• It identifies the spatiotemporal heterogeneity of CHDWDs, highlighting drylands as hotspots of stronger coupling and hyper-arid/humid regions as areas of more severe HDW intensification.
• The research reveals nonlinear and lagged responses of CHDWDs to distinct emission scenarios, showing stability before 2075 but a marked increase afterwards under SSP3-7.0 and SSP5-8.5.
• It refines the understanding of regional HDW/drought contributions to CHDWDs, projecting that HDWs will replace drought as the primary driver of CHDWD frequency in humid regions under SSP5-8.5, and confirming the consistent dominance of HDWs in humid-region CHDWD intensity across future scenarios.
• The findings offer a scientific basis for developing differentiated agricultural risk management and adaptation strategies tailored to specific climate zones in China.

Funding

• National Key Research and Development Program of China (2024YFF0809301)
• National Natural Science Foundation of China (42025104)
• Third Xinjiang Scientific Expedition Program (2022xjkk0100)

Citation

@article{Yao2025Increasing,
  author = {Yao, Feng and Sun, Fubao and Wang, Hong and Liu, Fa},
  title = {Increasing coupling of hot‒dry winds and drought across China: Observational evidence and future projection},
  journal = {Advances in Climate Change Research},
  year = {2025},
  doi = {10.1016/j.accre.2025.10.011},
  url = {https://doi.org/10.1016/j.accre.2025.10.011}
}