Xie et al. (2026) Disentangling internal and external impacts on increasing compound heat waves over the Yangtze River valley

Identification

• Journal: Weather and Climate Extremes
• Year: 2026
• Date: 2026-06-20
• Authors: Wenxin Xie, Botao Zhou, Jiuwei Zhao, Qiaohong Sun, Dapeng Zhang
• DOI: 10.1016/j.wace.2026.100927

Research Groups

• State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster, Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, China
• School of Atmospheric Sciences, Nanjing University of Information Science and Technology, China

Short Summary

This study disentangles the internal and external impacts on increasing compound heat waves over the Yangtze River valley. The results show that global warming contributes 36.9% to the total CHW changes, while decadal modes jointly contribute 63.1%. The study sheds light on CHW changes and its decadal prediction.

Objective

• Investigate the role of internal climate variability in modulating compound heat waves (CHWs) over the Yangtze River valley (YRV)
• Quantify the relative contributions from global warming (GW), Pacific Decadal Oscillation (PDO), and Atlantic Multidecadal Oscillation (AMO) to CHW changes

Study Configuration

• Spatial Scale: Regional scale, focusing on the Yangtze River valley in China
• Temporal Scale: 1961-2021, with a focus on decadal variability and trends

Methodology and Data

• Models used: Community Earth System Model (CESM) large ensemble simulations
• Data sources: CN05.1 gridded dataset, Climatic Research Unit (CRU) time series dataset version 4.07, European Centre for Medium-Range Weather Forecasts (ERA5), Hadley Centre Sea Ice and Sea Surface Temperature dataset, version 1 (HadISST1)

Main Results

• CHW frequency over the YRV shows an oscillatory upward trend from 1961 to 2021, with a marked weakening during 1981–1999 and a pronounced intensification afterwards
• Global warming contributes 36.9% to the total CHW changes, while decadal modes jointly contribute 63.1%
• The daytime maximum temperature in the YRV primarily exhibits a warm-cold-warm decadal variation, induced by the Pacific Decadal Oscillation (PDO)
• The nighttime minimum temperature is dominated by an increasing trend due to global warming and the subsequent influence of the Atlantic Multidecadal Oscillation (AMO)

Contributions

• This study provides new insights into the role of internal climate variability in modulating CHW changes over the YRV
• The results highlight the importance of considering both external forcing and internal variability when predicting future CHW risk

Funding

• Not specified in the provided text

Citation

@article{Xie2026Disentangling,
  author = {Xie, Wenxin and Zhou, Botao and Zhao, Jiuwei and Sun, Qiaohong and Zhang, Dapeng},
  title = {Disentangling internal and external impacts on increasing compound heat waves over the Yangtze River valley},
  journal = {Weather and Climate Extremes},
  year = {2026},
  doi = {10.1016/j.wace.2026.100927},
  url = {https://doi.org/10.1016/j.wace.2026.100927}
}