Work

Impacts of the local temperature anomalies over Mongolian Plateau on heavy rainfall events in north China during July 2023

Year: 2025

Type: article

Abstract: From July 29 to August 2, 2023, the western Pacific subtropical high (WPSH) exhibited a significant abnormal westward extension, forming a stable and persistent high-pressure barrier that led to heavy rainfall events (237HRE) in North China and resulted in flooding disasters in the Haihe River Basin. The diagnostics show that the positivetemperature anomalies over the Mongolian Plateau, as measured by the ERA5 and The Interactive Global Grand Ensemble (TIGGE) datasets, led to a westward extension of the WPSH during the 237HRE, which provided conditions for extreme precipitation. 237HER better forecasts benefit from WPSH being better forecasts.Utilizing the Weather Research and Forecasting (WRF) model, we conduct both control (CTL) and Temperature Anomaly Ensemble (TAVE) experiments to delve deeper into the influence of positive temperature anomalies over the Mongolian Plateau on the westward extension of the WPSH during the 237HRE period. The reduction of positive temperature anomalies weakens the westward extension of the WPSH, resulting in the position of the WPSH withdrawing to the east and weakening. Consequently, the typhoon residual vortex weakens and moves to the southeast with increased speed. Under these atmospheric circulation configurations, the moisture transport pathway also shifts eastward, leading to rainfall patterns expanding eastward and the intensity weakening in North China. These findings highlight the crucial role of local temperature anomalies over Mongolia in modulating the position of WPSH, which is essential for understanding and predicting typhoon pathways and the associated extreme weather events over monsoon regions.

Source: Weather and Climate Extremes

DOI: 10.1016/j.wace.2025.100758

Authors: Yunchang Cao, Ling Zhang, Haijun Zhao, Zhun Guo

Institutions: Nanjing University of Information Science and Technology, Ministry of Water Resources of the People's Republic of China, Shandong Meteorological Bureau, Chinese Academy of Sciences, Institute of Atmospheric Physics

Language: English

Topic: Meteorological Phenomena and Simulations

Subfield: Atmospheric Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

SDG: Climate action

Open Access status: gold

Estimated APC paid: $3,969