Using the long-term (2005–2019) observations from the Microwave Limb Sounder (MLS) onboard Aqua satellite, the present study delineates the variability of the lower stratospheric ozone (LSO) in the Asian Summer Monsoon Anticyclone (ASMA) region. The climatological features of LSO indicate a peak minimum in the southern flank of ASMA noticed by the geopotential measurements from MLS. Further, the temporal variability of LSO indicates significant interannual variability during the 15 years of MLS observations. Our analysis found that two prominent source regions control the LSO variability at interannual time scales in the ASMA region, associated with the Pacific and Indian Ocean sea surface temperatures. More importantly, the extreme (positive/negative) values in ozone anomalies coincide with the El Niño–Southern Oscillation(El Niño/La Niña) events. Further, the composite analysis reveals a significant change in the mean magnitude of LSO of about 10 ppb between El Niño and La Niña phases. The results indicate that reduced water vapor transport due to subsidence and suppressed convection during the El Niño phase leads to less mixing across the upper troposphere and lower stratosphere, therefore, causing higher concentrations of ozone and vice-versa during the La Niña phase. Hence, this study indicates a strong implication for the climatic perturbations over the ASMA region.

本研究使用Aqua卫星上的微波肢体测深仪（MLS）进行的长期（2005-2019）观测，描述了亚洲夏季风反旋风（ASMA）地区低空平流层臭氧（LSO）的变化性。LSO的气候特征表明，通过MLS进行的地势测量发现，ASMA的南侧面有一个最小峰。此外，LSO的时间变异性表明在15年的MLS观测期间，年际变异性显着。我们的分析发现，两个重要的源区在ASMA地区的年际尺度上控制着LSO的变化，与太平洋和印度洋的海表温度有关。更重要的是，臭氧异常的极端（正/负）值与厄尔尼诺-南方涛动（厄尔尼诺/拉尼娜）事件相吻合。此外，复合分析表明，在厄尔尼诺和拉尼娜相之间，LSO的平均幅度发生了约10 ppb的显着变化。结果表明，由于厄尔尼诺现象期间的沉降和对流抑制，减少了水蒸气的输送，导致对流层高层和低平流层之间的混合减少，因此，在拉尼娜相期间导致较高的臭氧浓度，反之亦然。因此，这项研究表明了对ASMA地区气候扰动的强烈暗示。结果表明，由于厄尔尼诺现象期间的沉降和对流抑制，减少了水蒸气的输送，导致对流层高层和低平流层之间的混合减少，因此，在拉尼娜相期间导致较高的臭氧浓度，反之亦然。因此，这项研究表明了对ASMA地区气候扰动的强烈暗示。结果表明，由于厄尔尼诺现象期间的沉降和对流抑制，减少了水蒸气的输送，导致对流层高层和低平流层之间的混合减少，因此，在拉尼娜相期间导致较高的臭氧浓度，反之亦然。因此，这项研究表明了对ASMA地区气候扰动的强烈暗示。