Yan et al. (2025) Rising temperatures intensify drought propagation and severity across the contiguous United States

Identification

• Journal: npj natural hazards.
• Year: 2025
• Date: 2025-10-03
• Authors: Hongxiang Yan, Ning Sun, Lili Yao, Travis Thurber, Jennie S. Rice
• DOI: 10.1038/s44304-025-00134-y

Research Groups

• Pacific Northwest National Laboratory, Richland, WA, USA

Short Summary

This study investigates how rising temperatures and changing precipitation influence the propagation of meteorological droughts (MD) into agricultural (AD) and hydrological droughts (HD) across the contiguous United States (CONUS). It reveals that warming intensifies drought propagation and severity, particularly in the Midwest and Southeast, while the Northeast shows reduced propagation due to increased year-round precipitation.

Objective

• To systematically assess how thermodynamic warming influences drought propagation probabilities across the CONUS.
• To investigate how different meteorological drought intensities lead to varying agricultural and hydrological drought intensities.
• To identify regions where warming exacerbates or mitigates drought propagation probabilities.

Study Configuration

• Spatial Scale: Contiguous United States (CONUS), focusing on 464 CAMELS (Catchment Attributes and Meteorology for Large-sample Studies) basins, with climate data at approximately 12 km spatial resolution. Basins are grouped into six regions: Northwest (NW), Southwest (SW), Midwest (MW), Great Plains (GP), Northeast (NE), and Southeast (SE).
• Temporal Scale: Historical period (1980–2019) and two 40-year future periods: NEAR future (2020–2059) and FAR future (2060–2099).

Methodology and Data

• Models used:
  • Community Land Model version 5 (CLM5) for land surface simulations, individually calibrated for each basin.
  • Weather Research and Forecasting (WRF) model (version 4.2.1) for dynamic downscaling of climate data.
  • Bayesian networks with Frank copula for probabilistic drought propagation modeling.
• Data sources:
  • Weather Research and Forecasting (WRF) Thermodynamic Global Warming (TGW) dataset: dynamically downscaled ERA5 reanalysis (historical baseline) and perturbed thermodynamics from a multi-model ensemble of CMIP6 global climate models (GCMs) (future projections under SSP245 and SSP585 scenarios).
  • CAMELS dataset: high-quality, unregulated daily streamflow measurements (1980–2014) for CLM5 calibration.
  • Drought indices: Standardized Precipitation Evapotranspiration Index (SPEI) for meteorological drought (MD), Standardized Soil Moisture Index (SSMI) for agricultural drought (AD), and Standardized Runoff Index (SRI) for hydrological drought (HD), all calculated at a 1-month timescale.

Main Results

• The Midwest and Southeast, key agricultural regions, show the largest increases in MD propagation to AD/HD, driven by rising temperatures and declining precipitation. For example, under the SSP585HOTTER_FAR scenario, the Southeast experiences a 54% increase in MD-AD and a 19% increase in MD-HD propagation probabilities for D1 MD events.
• In contrast, the Northeast shows reduced MD-AD and MD-HD propagation probabilities due to consistent year-round increases in precipitation.
• Higher-intensity AD/HD events become disproportionately more likely across most regions, while lower-intensity events (D0) decline, indicating a future shift toward more severe drought conditions.
• Lag times between MD-AD and MD-HD events are projected to increase across all six regions, suggesting MD events will take longer to propagate into AD or HD. For instance, in the Great Plains, the mean lag time between MD and AD increases from 1.4 months historically to 3.4 months under SSP585HOTTER_FAR.
• Despite projected increases in annual precipitation in some regions (e.g., Northwest, Great Plains, Northeast), all regions experience longer MD total duration and greater mean severity due to rising temperatures enhancing potential evapotranspiration.

Contributions

• Provides a systematic assessment of thermodynamic warming impacts on drought propagation probabilities across the CONUS using a well-calibrated land surface model, addressing a critical knowledge gap.
• Quantifies regional variations in drought propagation dynamics under future warming scenarios, highlighting the complex interplay of temperature, precipitation, and seasonality.
• Demonstrates that higher-intensity agricultural and hydrological droughts become disproportionately more likely, offering specific insights into future drought risk landscapes.
• Offers valuable insights for informing region-specific drought risk management strategies, water resource management, and agricultural adaptation practices.
• Emphasizes the need for enhanced early warning systems and extended forecasting horizons to account for evolving drought propagation dynamics and intensities.

Funding

• U.S. Department of Energy (DOE), Office of Science, MultiSector Dynamics, Earth, and Environmental System Modeling Program.
• National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility (Contract No. DE-AC02-05CH11231, NERSC award BER-ERCAP0027385).

Citation

@article{Yan2025Rising,
  author = {Yan, Hongxiang and Sun, Ning and Yao, Lili and Thurber, Travis and Rice, Jennie S.},
  title = {Rising temperatures intensify drought propagation and severity across the contiguous United States},
  journal = {npj natural hazards.},
  year = {2025},
  doi = {10.1038/s44304-025-00134-y},
  url = {https://doi.org/10.1038/s44304-025-00134-y}
}