Guo et al. (2025) What roles do dynamic and thermodynamic water vapor transport processes play in extreme precipitation over the Asian monsoon region?

Identification

• Journal: Atmospheric Research
• Year: 2025
• Date: 2025-11-22
• Authors: Lianyi Guo, Meiyi Hou, Yang Zhao, Wei Li, Yongping Wu, Guolin Feng
• DOI: 10.1016/j.atmosres.2025.108650

Research Groups

• College of Physical Science and Technology, Yangzhou University, Yangzhou, China
• Key Laboratory of Meteorological Disaster, Ministry of Education & Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science & Technology, Nanjing, China
• Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion, Yunnan University, Kunming, China
• State Key Laboratory of Physical Oceanography, College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao, China
• Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, Beijing, China

Short Summary

This study investigates the roles of dynamic and thermodynamic water vapor transport processes in extreme precipitation over the Asian monsoon region, revealing that while thermodynamic processes provide a robust basis, dynamic processes act as the direct trigger.

Objective

• To investigate linear and nonlinear relationships between extreme precipitation (EP) and concurrent precipitable water vapor (PWV) or vertically integrated water vapor transport (IVT) over the Asian monsoon region.
• To quantify the relative contributions of dynamic and thermodynamic water vapor transport processes to EP.

Study Configuration

• Spatial Scale: Asian monsoon (AM) region.
• Temporal Scale: Past decades.

Methodology and Data

• Models used: ERA5 reanalysis, 15 CMIP6 global climate models (GCMs).
• Data sources: Reanalysis data (ERA5), Global Climate Model output (CMIP6).

Main Results

• Consistently stronger correlations exist for precipitable water vapor (PWV) and extreme precipitation (EP) than for vertically integrated water vapor transport (IVT) and EP over the Asian monsoon region, observed in both ERA5 and CMIP6 models.
• Water vapor budget analysis reveals that the transient dynamic term dominates EP.
• The thermodynamic water vapor transport process provides the robust basis for EP, while the dynamic water vapor transport process serves as a direct trigger, jointly controlling EP.
• The apparent contradiction between stronger PWV-EP correlations and dynamic term dominance is attributed to greater variability in horizontal wind compared to specific humidity, which destabilizes IVT-EP correlations.

Contributions

• Provides a comprehensive investigation into the linear and nonlinear relationships between extreme precipitation and both precipitable water vapor and vertically integrated water vapor transport over the Asian monsoon region.
• Quantifies the relative contributions of dynamic and thermodynamic water vapor transport processes to extreme precipitation, clarifying their distinct roles.
• Reconciles seemingly contradictory findings regarding the predictive power of PWV/IVT and the dominance of dynamic terms in the water vapor budget.

Funding

Not available in the provided text.

Citation

@article{Guo2025What,
  author = {Guo, Lianyi and Hou, Meiyi and Zhao, Yang and Li, Wei and Wu, Yongping and Feng, Guolin},
  title = {What roles do dynamic and thermodynamic water vapor transport processes play in extreme precipitation over the Asian monsoon region?},
  journal = {Atmospheric Research},
  year = {2025},
  doi = {10.1016/j.atmosres.2025.108650},
  url = {https://doi.org/10.1016/j.atmosres.2025.108650}
}