Delayed effect of Arctic stratospheric ozone on tropical rainfall

作者:Xie, Fei; Zhang, Jiankai*; Sang, Wenjun; Li, Yang; Qi, Yulei; Sun, Cheng; Li, Yang; Shu, Jianchuan
来源:Atmospheric Science Letters, 2017, 18(10): 409-416.
DOI:10.1002/asl.783

摘要

The tropical precipitation has a wide effect on the tropical economics and social life. Many studies made efforts to improve the tropical precipitation forecast using tropical climate factors. This study, based on observations, found that Arctic stratospheric ozone (ASO) could exert a significant effect on the tropical precipitation, i.e. there is more (less) rainfall over the eastern Pacific and less (more) precipitation over the western Pacific when the ASO anomalies are lower (larger) than normal. It is because a decrease (increase) in ASO could affect El Nino (La Nina) events and lead to a weakened (enhanced) Walker circulation. Time-slice experiments confirmed that the ASO anomalies can force El Nino-Southern Oscillation-like anomalies of tropical sea surface temperature and subsequent tropical precipitation anomalies. In addition, the ASO variations could also change the occurrence probability of extreme precipitation in the tropics. During the anomalously low (high) ASO events, there are more occurrences of heavier precipitation over the eastern Pacific (western Pacific) and of lighter precipitation over the western Pacific (eastern Pacific). Furthermore, the ASO variations lead tropical rainfall by approximately 21 months, suggesting that the ASO can serve as a potentially effective predictor of tropical rainfall.