Linkage between ENSO and stratospheric ozone in East Asia and its impact mechanism

LI Yongchi; XU Feng; CHEN Yanxi; XU Siyi

doi:10.19513/j.cnki.hyqxxb.20241027001

Abstract：East Asia is one of the regions with the most potential for development and cooperation,and it is of scientific and social significance to study the impact of the El Niño-Southern Oscillation(ENSO),an interannual climate anomaly signal affecting stratospheric ozone,on the stratospheric ozone in East Asia.Based on the HadISST and ERA5 data from 1979 to 2021,the linkage between ENSO and the stratospheric ozone in East Asia and its impact mechanism are analyzed.The research findings are as follows.(1)ENSO mainly affects the ozone content and distribution in the lower stratosphere of East Asia,showing a significant positive correlation with the ozone content in the lower stratosphere in the ranges of 25°-30° N and 70°-120°E,with differences in the effects on positive and negative phases.(2)ENSO influences the stratospheric atmosphere of East Asia through the anomalies of Rossby wave activities.The ENSO-induced anomalies of Rossby wave activities are dominated by the lower stratospheric influence,with positive phases accompanying Rossby wave's upload at low latitudes and affecting East Asia through the northwestward wave flux anomalies from the tropical eastern-central Pacific to East Asia.The wave activities cause the atmosphere in East Asia to undergo meridional shifts and vertical motions,leading to the anomalous ozone content and distribution in this region.(3)In addition,it is found that there is an interdecadal variation in the relationship between ENSO and the stratospheric ozone in East Asia from 1979 to 2021,which is attributed to the change in the spatial correlation pattern between ozone and sea surface temperature in the two periods.