Abulikemu et al. (2025) A case study on convection initiation mechanisms of an extreme rainstorm in Hotan, Xinjiang, NW China

Identification

• Journal: Atmospheric Research
• Year: 2025
• Date: 2025-10-10
• Authors: Abuduwaili Abulikemu, Qi Sun, Lianmei Yang, Jianjun Hu, Yong Zeng, Jiangang Li, Dawei An
• DOI: 10.1016/j.atmosres.2025.108533

Research Groups

• Xinjiang Key Laboratory of Oasis Ecology, College of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi, China
• Xinjiang Field Scientific Observation and Research Station for the Oasisization Process in the Hinterland of the Taklamakan Desert, Yutian, Xinjiang, China
• Changyu school of Guangming District, Shenzhen, China
• Institute of Desert Meteorology, China Meteorological Administration, Urumqi, China
• Xinjiang Innovation Institute of Cloud Water Resource Development and Utilization, Urumqi, China
• Xinjiang Cloud Precipitation Physics and Cloud Water Resources Development Laboratory, Urumqi, China
• Field Scientific Observation Base of Cloud Precipitation Physics in West Tianshan Mountains, Xinyuan, China
• Xinjiang Air Traffic Management Bureau of Civil Aviation of China, Urumqi, China
• Xinjiang Meteorological Observatory, Urumqi, China

Short Summary

This study investigates the convection initiation mechanisms of an extreme rainstorm in Hotan, Xinjiang, in June 2021, revealing that a boundary layer convergence line, formed by a cold pool and a low-level easterly jet, was crucial for continuous convective initiation and rapid development.

Objective

• To investigate the convection initiation (CI) mechanisms of an extreme rainstorm event that occurred in June 2021 in Hotan, Xinjiang, Northwest China.

Study Configuration

• Spatial Scale: Regional scale, focusing on Hotan, Xinjiang, Northwest China.
• Temporal Scale: A specific extreme rainstorm event in June 2021.

Methodology and Data

• Models used: Weather Research and Forecasting (WRF) model.
• Data sources: Automatic weather stations (observational data), Fengyun-4A satellite data, reanalysis data, WRF simulation data.

Main Results

• Continuous convection initiation (CI) sites were observed near a boundary layer convergence line (BLCL).
• The BLCL was generated by the merger of a cold pool and a low-level easterly jet (LLEJ).
• Most initiated convective cells rapidly developed and merged into a mesoscale convective system (MCS), which caused the heavy precipitation.
• Diagnostic analysis of the vertical momentum budget along Lagrangian backward trajectories showed that dynamic acceleration was responsible for the vertical acceleration of air parcels during the rapid-ascending stage of CI.
• The "Extension term" played a decisive role in dynamic acceleration, primarily attributed to low-level convergence within the BLCL.
• The "Twisting term" provided negative contributions to dynamic acceleration, while the "Curvature term" was negligibly small.

Contributions

• Provides a detailed case study and diagnostic analysis of convection initiation mechanisms for an extreme rainstorm in a data-sparse region of Northwest China.
• Identifies the specific role of a boundary layer convergence line, formed by the interaction of a cold pool and a low-level easterly jet, as a key factor for CI.
• Quantifies the contributions of different terms (Extension, Twisting, Curvature) to the vertical acceleration of air parcels during CI using a Lagrangian approach.

Funding

• Not specified in the provided text.

Citation

@article{Abulikemu2025case,
  author = {Abulikemu, Abuduwaili and Sun, Qi and Yang, Lianmei and Hu, Jianjun and Zeng, Yong and Li, Jiangang and An, Dawei},
  title = {A case study on convection initiation mechanisms of an extreme rainstorm in Hotan, Xinjiang, NW China},
  journal = {Atmospheric Research},
  year = {2025},
  doi = {10.1016/j.atmosres.2025.108533},
  url = {https://doi.org/10.1016/j.atmosres.2025.108533}
}