中部型ENSO和平流层准两年振荡对冬季北半球平流层臭氧的联合调制作用

Joint impacts of ENSO Modoki and QBO on stratospheric ozone in winter in the Northern Hemisphere

  • 摘要: 利用观测和再分析资料通过合成分析方法,研究了中部型ENSO和平流层准两年振荡(QBO)对冬季北半球平流层臭氧的独立影响和联合调制作用。研究表明,北半球平流层臭氧在中部型厄尔尼诺年增加,而在中部型拉尼娜年减少;准两年振荡东风位相年份,北半球平流层臭氧增加,准两年振荡西风位相结果则相反。相比之下,北半球中、高纬度平流层臭氧异常对准两年振荡活动的响应明显小于其对ENSO活动的响应。进一步研究发现,准两年振荡东风位相会加强中部型厄尔尼诺事件引起的北半球平流层臭氧的增加,而减弱中部型拉尼娜事件造成的平流层臭氧的减少。在准两年振荡西风位相下,中部型厄尔尼诺事件仅导致北半球平流层臭氧含量少量升高,而中部型拉尼娜事件期间臭氧会大幅度减少。因此,准两年振荡东风位相会加强中部型厄尔尼诺事件对北半球平流层臭氧的影响,而减弱中部型拉尼娜事件对北半球平流层臭氧的影响。准两年振荡西风位相会减弱中部型厄尔尼诺而加强中部型拉尼娜事件对北半球平流层臭氧的影响。

     

    Abstract: Composite analysis is applied in the present study to investigate independent and joint impacts of the second type of El Niño-Southern Oscillation (ENSO Modoki) and the Quasi-biennial Oscillation (QBO) on stratospheric ozone in the Northern Hemisphere (NH) in winter using observed ozone data and reanalysis data. The analysis reveals that stratospheric ozone in the NH in winter increases during El Niño Modoki events but decreases during La Niña Modoki events. Stratospheric ozone in the NH in winter increases during the east wind phase of the QBO (EQBO) and decreases during the west wind phase of the QBO (WQBO). In contrast, stratospheric ozone anomalies in the middle and high latitudes caused by ENSO activities are evidently larger than those related to the QBO phases. Further analysis indicates that during the EQBO phase, stratospheric ozone anomalies in the NH are amplified during El Niño Modoki events but reduced during La Niña Modoki events. During the WQBO phases, El Niño Modoki events only slightly increase the stratosphere ozone concentration in the NH in winter, while the ozone concentration is greatly reduced during La Niña Modoki events. Therefore, the EQBO enhances the effect of El Niño Modoki events on stratospheric ozone in the NH, but weakens the effect of La Niña Modoki events. The WQBO weakens the effect of El Niño Modoki events but intensifies the effect of La Niña Modoki events on stratospheric ozone in the NH.

     

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