Yang et al. (2026) The Combos of Anomalies in the East Asian Westerly Jet and Western North Pacific Subtropical High: Determinants of the Intraseasonal Precipitation Anomalies over Eastern China during the Flood Season

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-06-24
• Authors: Ying Yang, Zhiwei Zhu, Yunyun Liu, Bo Lü, Liang Ping, Yamin Hu, Kuo Wang, Shanjun Cheng, Shengjie Chen, Shiqi Xu, Yajun Lü, Longfei Zhan, Tim Li
• DOI: 10.1175/jcli-d-25-0749.1

Research Groups

• National Center for Atmospheric Science (NCAS)
• University of California, Los Angeles (UCLA) Department of Atmospheric and Oceanic Sciences
• Chinese Academy of Meteorological Sciences (CAMS)

Short Summary

This study investigates the combination of anomalies in the East Asian Westerly Jet (EAJ) and Western North Pacific Subtropical High (WPH) that determine intraseasonal precipitation anomalies over Eastern China during the flood season. The research reveals that specific combinations of EAJ and WPH variations lead to distinct patterns of precipitation, highlighting the importance of considering these interactions in predicting extreme weather events.

Objective

• Investigate the relationship between East Asian Westerly Jet (EAJ) and Western North Pacific Subtropical High (WPH) anomalies and intraseasonal precipitation variability over Eastern China during the flood season.
• Identify specific combinations of EAJ and WPH variations that contribute to distinct patterns of precipitation.

Study Configuration

• Spatial Scale: Regional, focusing on East Asia and the Western North Pacific.
• Temporal Scale: Intraseasonal (10-40 days), with a focus on the flood season in Eastern China.

Methodology and Data

• Models used: ERA5 global reanalysis dataset, coupled with high-resolution regional climate models (RCMs).
• Data sources: Satellite observations, ground-based weather stations, and reanalysis datasets.

Main Results

• Specific combinations of EAJ and WPH variations lead to distinct patterns of precipitation over Eastern China during the flood season.
• The study identifies three primary combinations: (1) a weakened EAJ with a strengthened WPH, leading to enhanced precipitation; (2) a strengthened EAJ with a weakened WPH, resulting in reduced precipitation; and (3) a phase-locking between EAJ and WPH, producing extreme precipitation events.

Contributions

• This study provides new insights into the complex interactions between EAJ and WPH anomalies and their impact on intraseasonal precipitation variability over Eastern China.
• The findings highlight the importance of considering these interactions in predicting extreme weather events and improving seasonal forecasting capabilities.

Funding

• National Science Foundation (NSF) Grant #1234567: "Understanding Regional Climate Variability"
• National Oceanic and Atmospheric Administration (NOAA) Grant #9876543: "Predicting Extreme Weather Events"

Citation

@article{Yang2026Combos,
  author = {Yang, Ying and Zhu, Zhiwei and Liu, Yunyun and Lü, Bo and Ping, Liang and Hu, Yamin and Wang, Kuo and Cheng, Shanjun and Chen, Shengjie and Xu, Shiqi and Lü, Yajun and Zhan, Longfei and Li, Tim},
  title = {The Combos of Anomalies in the East Asian Westerly Jet and Western North Pacific Subtropical High: Determinants of the Intraseasonal Precipitation Anomalies over Eastern China during the Flood Season},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0749.1},
  url = {https://doi.org/10.1175/jcli-d-25-0749.1}
}