Drying Over Eastern China Driven by the Depletion of Arctic Stratospheric Ozone During Boreal Spring

• Published in: Geophysical research letters 2024-04, Vol.51 (8), p.n/a
• Main Authors: Hu, Dingzhu, Zhang, Zhuohua, Guan, Zhaoyong
• Format: Article
• Language: English
• Subjects: Agricultural production; Crop planting; Drying; Evaporation; Food production; Hadley circulation; Jet stream; Ozone; Precipitation; Precipitation variability; Spring; Spring (season); Spring precipitation; Stratosphere; Subtropical jet stream; Tropopause; Variability; Weather forecasting; Wetting
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2023GL108008

Given the significant importance of spring precipitation for agricultural production in China and the presence of the spring predictability barrier, scientists have dedicated extensive efforts to understand the factors influencing spring precipitation variability and explore new predictors. However, the effects of Arctic stratospheric ozone (ASO) on precipitation in China during boreal spring, if any, and the underlying mechanisms remain unclear. We found the robust influences of March ASO on the differences in the precipitation and evaporation in April over Eastern China during 1980–2020. When ASO decreases in March, it tends to result in a higher and colder tropopause in the polar, a stronger subtropical jet stream, an intensified local Hadley circulation accompanied by anomalous downward motion over Eastern China, and consequently, drying in this region, and vice versa. These findings suggest that the likelihood of April moistening over East Asia may be potentially predicted by employing the ASO index. Plain Language Summary Food production in East Asia, which is home to a quarter of the world's population, holds immense importance. The spring season in this region marks the crop planting period, making the precipitation during this time crucial for agricultural production. However, it is challenging to predict spring moistening/drying over East Asia. Therefore, there is a need for new predictors to enhance our understanding of spring precipitation variability. Whether a connection exists between Arctic stratospheric ozone (ASO) and spring precipitation over EC has remained unknown. Here, we have highlighted a strong relationship between ASO in March and moistening over EC in April, particularly in the middle and lower reaches of the Yangtze River (YRB). Specifically, an increase (decrease) in March ASO corresponds to moistening (drying) over YRB in April. The implications of these findings are significant for forecasting spring precipitation over East Asia, which is crucial for agricultural planning and production. Key Points There are robust influences of March Arctic stratospheric ozone (ASO) on the precipitation in April over Eastern China (EC) during 1980–2020 Depletion of ASO in March tends to result in decreased precipitation over EC in April Decreased ASO results in the higher but warmer tropopause, stronger subtropical jet, and anomalous downward motion over EC