Influence of Arctic stratospheric ozone in March on precipitation in eastern China during the boreal spring

The influence of Arctic stratospheric ozone (ASO) in March on precipitation in eastern China during the boreal spring has been investigated by using observations, reanalysis datasets, and historical simulations from CMIP6. Results show a robust in-phase relationship between March ASO and precipitation in eastern China in April and May on interannual timescale during 1980–2020, with the strongest positive correlation in April in the Yangtze River Basin (YRB) and in May in South China (SC). A (an) decrease (increase) of ASO tends to result in a (an) decrease (increase) in precipitation by a combination of factors, including a lack (sufficiency) of water vapor, vigorous downward (upward) motion, and a negative (positive) North Atlantic-Ural Mountain-East Asia (NAULEA)-like wave train. The shift in the strongest positive correlation center of ASO and precipitation from April at the YRB to May at the SC is closely linked to the shift in the most pronounced center of upward movement from April to May. Additionally, anomalies in the North Atlantic Oscillation (NAO) in April play an important role in connecting ASO to precipitation in eastern China. A decrease of March ASO tends to result in a positive phase of NAO, which triggers a negative NAULEA-like wave train along with a strengthened East Asian jet stream. The modification of local circulation results in a decrease in precipitation in eastern China. This study suggests that the March ASO can serve as a potential predictor for precipitation forecasts in eastern China during the boreal spring.