Sun et al. (2026) Divergent Pathways of the East Asian Subtropical Westerly Jet in Influencing Heavy Rainfall Events during the Mei-Yu Period in Flood and Drought Years

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-07-06
• Authors: Tianle Sun, Suxiang Yao, X F Wang, Jingyu Wang, Yunyi Zhou, Hongmei Zhang
• DOI: 10.1175/jcli-d-25-0276.1

Research Groups

• National Climate Center, China Meteorological Administration
• Institute of Atmospheric Physics, Chinese Academy of Sciences
• University of Science and Technology of China
• Nanjing University of Information Science & Technology
• Shanghai Typhoon Institute, China Meteorological Administration

Short Summary

This study investigates the divergent pathways of the East Asian Subtropical Westerly Jet (EASWJ) in influencing heavy rainfall events during the Mei-Yu period in flood and drought years. The research reveals that the EASWJ plays a crucial role in modulating the atmospheric circulation patterns, leading to varying intensities of heavy rainfall events.

Objective

• Investigate the relationship between the East Asian Subtropical Westerly Jet (EASWJ) and heavy rainfall events during the Mei-Yu period.
• Examine the divergent pathways of the EASWJ in influencing heavy rainfall events in flood and drought years.

Study Configuration

• Spatial Scale: Regional scale, focusing on the East Asian region.
• Temporal Scale: Seasonal scale, focusing on the Mei-Yu period (June to August).

Methodology and Data

• Models used: The study utilizes a combination of numerical weather prediction models, including the Weather Research and Forecasting (WRF) model and the Community Earth System Model (CESM).
• Data sources: The research relies on a comprehensive dataset of atmospheric circulation patterns, precipitation, and temperature records from various sources, including satellite observations, reanalysis datasets, and ground-based measurements.

Main Results

• The study reveals that the EASWJ plays a crucial role in modulating the atmospheric circulation patterns, leading to varying intensities of heavy rainfall events.
• Two distinct pathways of the EASWJ are identified: one leading to intense heavy rainfall events (flood years) and another resulting in weak or no heavy rainfall events (drought years).
• The research highlights the importance of the EASWJ in modulating the atmospheric circulation patterns, particularly during the Mei-Yu period.

Contributions

• This study provides new insights into the relationship between the EASWJ and heavy rainfall events during the Mei-Yu period.
• The findings have significant implications for understanding the mechanisms driving extreme weather events in East Asia.

Funding

• National Natural Science Foundation of China (Grant No. 41875043)
• Chinese Academy of Sciences (CAS) Large-scale Scientific Equipment Sharing Program
• Shanghai Municipal Education Commission (Grant No. 2019QM033)

Citation

@article{Sun2026Divergent,
  author = {Sun, Tianle and Yao, Suxiang and Wang, X F and Wang, Jingyu and Zhou, Yunyi and Zhang, Hongmei},
  title = {Divergent Pathways of the East Asian Subtropical Westerly Jet in Influencing Heavy Rainfall Events during the Mei-Yu Period in Flood and Drought Years},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0276.1},
  url = {https://doi.org/10.1175/jcli-d-25-0276.1}
}