Wang et al. (2026) Spatiotemporal evolution and drivers of compound dry-hot and wet-hot events in a changing climate

Identification

• Journal: Journal of Hydrology
• Year: 2026
• Date: 2026-10-14
• Authors: Chao Wang, Fanli Sun, Shuzhe Huang, Wei Wang
• DOI: 10.1016/j.jhydrol.2026.136629

Research Groups

• State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan, China
• State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China

Short Summary

This study assesses the global spatiotemporal evolution and drivers of Compound Dry-Hot Events (CDHEs) and Compound Wet-Hot Events (CWHEs) from 1961 to 2100 using CMIP6 simulations. It finds that both event types have intensified since the 1990s, with CWHEs projected to become increasingly dominant and severe by the late 21st century, primarily driven by hot conditions.

Objective

• To assess the global spatiotemporal evolution and changes of Compound Dry-Hot Events (CDHEs) and Compound Wet-Hot Events (CWHEs) from 1961 to 2100 under historical and future climate change scenarios (CMIP6 SSPs).
• To attribute these changes to thermal and precipitation factors using copula decomposition and explore associated physical pathways through land-atmosphere diagnostics.

Study Configuration

• Spatial Scale: Global
• Temporal Scale: 1961 to 2100 (historical period and future projections under four Shared Socioeconomic Pathway (SSP) scenarios)

Methodology and Data

• Models used: Multi-model CMIP6 simulations
• Data sources: CMIP6 simulations (historical period and four SSP scenarios). Diagnostic land-atmosphere analyses use vapor pressure deficit, relative humidity, and soil moisture. A copula-based return-period decomposition is used for attribution.

Main Results

• Both CDHEs and CWHEs have intensified globally since the 1990s, exhibiting distinct spatial patterns.
• CDHEs show stronger increases in arid and semi-arid regions.
• CWHEs intensify more rapidly in humid climatic zones and high-latitude regions.
• Future projections indicate continued increases in compound heat risks under all SSPs, with the most pronounced increases under high-emission scenarios.
• By the late 21st century, CWHEs are projected to become increasingly dominant, with faster increases in severity and duration compared to CDHEs.
• Copula decomposition analysis reveals that hot conditions are the dominant driver for both event types.
• Diagnostic land-atmosphere analysis identifies vapor pressure deficit as the most consistent predictor associated with both CDHEs and CWHEs.

Contributions

• Provides a consistent framework for comparing the global evolution and changes of two contrasting compound heat extremes (CDHEs and CWHEs) under climate change.
• Offers a comprehensive attribution of changes in CDHEs and CWHEs to thermal and precipitation factors using copula decomposition.
• Identifies vapor pressure deficit as a consistent physical predictor for both event types through diagnostic land-atmosphere analyses.
• Highlights the growing importance of wet-heat hazards and provides a basis for developing differentiated adaptation strategies.

Funding

• Not specified in the provided text.

Citation

@article{Wang2026Spatiotemporal,
  author = {Wang, Chao and Sun, Fanli and Huang, Shuzhe and Wang, Wei},
  title = {Spatiotemporal evolution and drivers of compound dry-hot and wet-hot events in a changing climate},
  journal = {Journal of Hydrology},
  year = {2026},
  doi = {10.1016/j.jhydrol.2026.136629},
  url = {https://doi.org/10.1016/j.jhydrol.2026.136629}
}