Sabut et al. (2026) Global expansion of compound drought–heatwave risk

Identification

• Journal: Nature Communications
• Year: 2026
• Date: 2026-10-14
• Authors: Amitesh Sabut, Ashok Kumar Mishra, Lai-Yung Ruby Leung, Dara Entekhabi
• DOI: 10.1038/s41467-026-78045-3

Research Groups

• Zachry Department of Civil & Environmental Engineering, Texas A&M University, College Station, TX, USA
• Atmospheric, Climate & Earth Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA
• Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA

Short Summary

This study investigates the evolution and spatial reorganization of compound drought-heatwave (CDHW) events globally, revealing that these events systematically displace over time rather than remaining stationary, thereby expanding the footprint of compound stress.

Objective

• To track the evolution, expansion, and spatial reorganization of compound drought-heatwave (CDHW) hotspots across global land regions, addressing the largely unexplored nature of their spatiotemporal dynamics.

Study Configuration

• Spatial Scale: Global land regions, with specific focus on Northern Hemisphere mid-latitudes and identified emerging hotspots (European Plains, western North America, Amazon, West African Sahel, Central Asia, northern Australia).
• Temporal Scale: Event-based, with typical durations of 6–12 days for contiguous events. The study tracks over 2500 CDHW events.

Methodology and Data

• Models used: Three-dimensional connected-component (CC3D) labeling approach for tracking CDHW events.
• Data sources: Historical climate data (implied, for identifying and tracking CDHW events).

Main Results

• Compound drought-heatwave (CDHW) events, often treated as spatially stationary extremes, exhibit systematic displacement over time.
• Larger and longer-lasting CDHW events tend to travel farther and faster, expanding the spatial footprint of compound heat and moisture stress.
• Most contiguous CDHW events persist for 6–12 days, displace by up to approximately 500 km, and reach peak daily spatial extents of 2 × 10⁵ to 5 × 10⁵ km².
• CDHW migration is strongest in the Northern Hemisphere mid-latitudes and is predominantly eastward.
• Emerging hotspots of increasing CDHW migration potential are identified across the European Plains, western North America, the Amazon, the West African Sahel, Central Asia, and northern Australia.
• These shifts are linked to evolving large-scale atmospheric circulation and are reinforced by downstream drying through reduced moisture transport and strengthened land–atmosphere coupling.

Contributions

• Provides the first systematic tracking of the spatiotemporal displacement and reorganization of compound drought-heatwave events globally, challenging the assumption of their spatial stationarity.
• Quantifies key characteristics of CDHW migration, including typical duration, displacement distance, and spatial extent.
• Identifies specific global regions experiencing increasing CDHW migration potential and links these shifts to underlying atmospheric and land–atmosphere coupling mechanisms.
• Highlights the expanded exposure risk to compound heat and moisture stress, particularly for vulnerable agricultural and grazing-dependent regions.

Funding

• National Science Foundation (NSF) under Award No. 2445027.
• Office of Science, U.S. Department of Energy, Biological and Environmental Research through the Water Cycle: Modeling of Circulation, Convection, and Earth System Mechanisms (WACCEM) scientific focus area.
• Integrated Coastal Modeling project supported by the Regional and Global Model Analysis program area.
• Battelle Memorial Institute under Contract DE-AC-05-76RL01830 (for PNNL operation for the Department of Energy).

Citation

@article{Sabut2026Global,
  author = {Sabut, Amitesh and Mishra, Ashok Kumar and Leung, Lai-Yung Ruby and Entekhabi, Dara},
  title = {Global expansion of compound drought–heatwave risk},
  journal = {Nature Communications},
  year = {2026},
  doi = {10.1038/s41467-026-78045-3},
  url = {https://doi.org/10.1038/s41467-026-78045-3}
}