夏季青藏高原O_3低值与南亚高压东西振荡的关系

Relationships between Low O_3 and the Longitudinal Oscillation of the South Asia High over the Tibetan Plateau in Summer

利用O3监测仪(Ozone Monitoring Instrument,OMI)卫星O3廓线资料和NCEP/NCAR再分析资料,研究了2006年夏季南亚高压偏西型和偏东型条件下青藏高原地区O3垂直结构和变化特征差异。结果表明,夏季南亚高压东西振荡与青藏高原O3分布存在密切的关系,在西(东)部型南亚高压条件下,夏季青藏高原地区大气、对流层和平流层O3柱总量低值中心均偏西(东),位于青藏高原西(东)部,尤其是在南亚高压最强的对流层顶附近,O3低值中心位于南亚高压中心。在西部型南亚高压条件下,低纬度地区含低浓度O3的空气不易到达高原上空,青藏高原上空的O3低值较弱。在东部型南亚高压条件下,从低纬度经中南半岛西北方向孟加拉湾带来的低纬地区低浓度O3,在青藏高原上空堆积,形成O3低值中心。因此,南亚高压东西振荡是影响青藏高原上空O3低值中心变化的重要因素之一,该研究对理解南亚高压东西振荡机制及提高我国气候预测具有一定的指导意义。

Based on the data sets of Ozone Monitoring Instrument （OMI） O3 profiles over the Tibetan Plateau and the NCEP/NCAR reanalysis data in July 2006,the relationships between low O3 over the Tibetan Plateau and the longitudinal oscillation of the South Asia high are analyzed. The results show that the longitudinal oscillation of the South Asia high has an obvious correlation with the low O3 over the Tibetan Plateau. When the South Asia high exhibits the east （west） phase,the low O3 centers of the total column O3,the tropospheric column O3,and the stratospheric column O3 are located in the east （west） of the Tibetan Plateau. During the west phase of the South Asia high,the low O3 air is difficult to transport to the top of the Tibetan Plateau and the low O3 is weak over the Tibetan Plateau. While during the east phase of the South Asia high,the low O3 air from the Bay of Bengal is transported northward to the middle troposphere over the Tibetan Plateau by southeast currents and piles over the Tibetan Plateau,forming the low O3. So the longitudinal oscillation of the South Asia high is one of the most important factors contributing to the variation of the low O3 over the Tibetan Plateau,and the study is good for understanding the mechanism of the longitudinal oscillation of the South Asia high and improving the quality of climate forecast in China.