ISSN 1000-0526
CN 11-2282/P
CN 11-2282/P
Research on the Characteristics of Circulation and Water Vapor Conditions of the
- Article
- Figures
- Metrics
- Preview PDF
- Reference
- Related
- Cited by
- Materials
Abstract:
Based on the surface meteorological observation precipitation data and the ERA5 reanalysis data, the rainstorm that occurred in North China from July 23 to 30 in 2025 is investigated from the perspectives of circulation evolution and water vapor conditions. The findings reveal that the rainstorm was characterized by its prolonged duration and extensive impact area. The spatial distribution of precipitation markedly differed from that of previous rainstorms. The main precipitation zone stretched over 1,000 km from east to west, exhibiting a nearly zonal pattern. Two main rain belts were identified, situated in the Plateau (a secondary terrain region) and the plain area (a tertiary terrain region) of North China, respectively.The anomalous large-scale circulation patterns were observed during this precipitation event. The abnormally persistent northward-shifted Western Pacific Subtropical High, a stagnant westerly shortwave trough, and the shear lines generated in the lower troposphere were the key weather systems directly influencing the rainstorm. Throughout the precipitation evolution, the South Asian High and the Western Pacific Subtropical High underwent a reciprocal advancing and retreating process. The low-latitude weather system remained active, with typhoons Francisco and Co-may emerging continuously near East China coastlines, supplying ample water vapor for the precipitation. The westward expansion of the Western Pacific Subtropical High and its surrounding anticyclonic circulation dominated the eastern side of the Qinghai-Tibet Plateau, fostering two water vapor transport belts and convergence zones within the main precipitation area, which corresponded to the two rain belts in the secondary and tertiary terrain regions.The water vapor budget analysis indicates that the primary sources of water vapor in the tertiary terrain region were its southern and western boundaries (with outflow from the secondary terrain region). Compared to the secondary terrain region, the tertiary terrain region exhibited weaker water vapor inflow and net gain, it demonstrated a higher precipitation conversion rate and greater precipitation volume.
Keywords:
Project Supported:
Clc Number:
Mobile website
