Report Time

July 1, 2024 (Monday) 14:00 - 15:30

Special Guest

Dr. Sun Juanzhen, a researcher at the National Center for Atmospheric Research (NCAR), Chair of the Short-Term Forecasting Research Program, a member of the WMO Nowcasting Working Group, and a Fellow of the American Meteorological Society (AMS Fellow). Dr. Sun, an internationally renowned expert in data assimilation and convective weather forecasting, has long been engaged in research on convective-scale data assimilation and short-term forecasting of severe convective weather. As one of the pioneers, she developed the rapid update cycle four-dimensional variational assimilation method for effectively assimilating dense observational data from weather radars and automatic stations into high-resolution numerical models, which has gained widespread application internationally.

Report Content

The unprecedented rainstorm in Zhengzhou on July 20, 2021, set a record for hourly precipitation in mainland China, affecting 14.786 million people across 150 counties (cities, districts) in Henan Province, with 398 deaths and missing persons, including 380 in Zhengzhou alone, and resulting in direct economic losses of 120.06 billion yuan. While the large-scale forcing characteristics of extreme rainstorms have been extensively studied, the corresponding key mesoscale and microscale characteristics remain to be clarified. This report, based on the rapid update cycle four-dimensional variational assimilation system and assimilating multi-source dense meteorological observational data (radar, automatic stations, etc.), delves into the mesoscale and microscale characteristics and key factors in the formation and development of this extraordinary rainstorm event in Zhengzhou.