He et al. (2025) Spring extreme heat in the Indochina Peninsula enhances the prediction skill of summer precipitation in Central China

Identification

• Journal: Atmospheric Research
• Year: 2025
• Date: 2025-12-17
• Authors: Yihua He, Wei Lou, Cheng Sun, Menghao Dong, Zichen Song, Linfeng Shi, Yiying Tong
• DOI: 10.1016/j.atmosres.2025.108710

Research Groups

• State Key Laboratory of Remote Sensing and Digital Earth, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
• Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210049, China

Short Summary

This study investigates how spring extreme heat in the Indochina Peninsula (ICP) influences summer precipitation in Central China (CC), proposing that ICP extreme heat enhances CC summer precipitation through a land-atmosphere feedback loop, soil moisture memory, and subsequent anticyclonic circulation. The findings demonstrate that incorporating these land surface processes significantly improves the prediction skill of summer precipitation in Central China.

Objective

• To elucidate the mechanisms through which land surface processes, specifically extreme heat events (TX90P) over the Indochina Peninsula (ICP) during March–April-May (MAM), enhance June–July-August (JJA) precipitation in Central China (CC).

Study Configuration

• Spatial Scale: Indochina Peninsula (ICP), Central China (CC), and Western Pacific (WP). Regional scale.
• Temporal Scale: Spring (March-April-May) extreme heat influencing Summer (June-July-August) precipitation. Inter-seasonal.

Methodology and Data

• Models used: Linear Baroclinic Model (LBM), Multiple Linear Regression model.
• Data sources: Observed data (for JJA CC precipitation), model outputs.

Main Results

• Extreme heat events (TX90P) over the ICP during MAM establish a self-reinforcing feedback loop through land-atmosphere energy and moisture exchange, amplifying heat intensity.
• These extreme heat events are accompanied by high-pressure systems with anomalous subsidence, suppressing precipitation and reducing soil moisture (SM).
• The resulting dry soil creates a positive feedback mechanism, allowing anomalous SM reduction to persist into JJA due to a soil moisture memory effect.
• This soil moisture memory-induced drought weakens vertical motion over the ICP, fostering an anticyclonic circulation pattern spanning the ICP and Western Pacific.
• The anticyclonic circulation strengthens southwesterly winds, which transport moisture northeastward towards Central China, leading to enhanced JJA precipitation.
• Simulations with a Linear Baroclinic Model (LBM) confirm that ICP extreme heat events generate southwesterly wind anomalies, facilitating moisture transport to CC.
• A multiple linear regression model, incorporating MAM TX90P, preceding winter El Niño-Southern Oscillation (ENSO), and preceding winter Indian Ocean Dipole (IOD), effectively reproduces observed JJA CC precipitation with a correlation coefficient (r) of 0.62.
• Incorporating extreme heat-related land surface processes significantly improves precipitation prediction skill compared to models relying solely on oceanic variability.

Contributions

• Identifies a novel teleconnection mechanism linking spring extreme heat in the Indochina Peninsula to summer precipitation in Central China via land-atmosphere feedback and soil moisture memory.
• Demonstrates that land surface processes, specifically extreme heat, are crucial for improving the prediction skill of summer precipitation in Central China, offering a significant advancement over models based solely on oceanic variability.
• Provides a new, effective predictor (ICP MAM TX90P) for summer precipitation in Central China.

Funding

Not explicitly mentioned in the provided text.

Citation

@article{He2025Spring,
  author = {He, Yihua and Lou, Wei and Sun, Cheng and Dong, Menghao and Song, Zichen and Shi, Linfeng and Tong, Yiying},
  title = {Spring extreme heat in the Indochina Peninsula enhances the prediction skill of summer precipitation in Central China},
  journal = {Atmospheric Research},
  year = {2025},
  doi = {10.1016/j.atmosres.2025.108710},
  url = {https://doi.org/10.1016/j.atmosres.2025.108710}
}