平流层爆发性增温中平流层环流及化学成分变化过程研究

Impacts of the Stratospheric Sudden Warming on the Stratospheric Circulation and Chemical Tracers

利用欧洲中期天气预报中心（ECMWF）气象分析场、欧洲空间局ENVISAT／MIPAS卫星观测资料以及平／对流层大气化学输送模式MOZART-3综合分析了2003-2004年冬季北半球爆发性增温事件对于平流层大气环流、物质输送以及对流层顶附近臭氧通量等多方面的影响。结果表明：①本次增温过程持续时间长、强度大，平流层极涡从高层向下逐层分裂，增温效应作用到大气较低层，当纬向东风形成并维持后极涡又自上向下逐层恢复；②SSW过程前后行星波活动频繁，有长时间多次的上传，且以1波作用为主，2波对其进行补充；⑧在θ-PVLAT坐标中分析发现SSW扰动过程中平流层中存在一对向极、向下的传播模态，相应的对流层中有一向赤道的传播模态，不同符号的纬向风、温度异常信号沿这两个模态传播，且上、下层传播模态在时间上存在着一定的联系；④增温过程中行星波活动引起的向极输送以及极区垂直运动的变化，共同影响了平流层的物质输送过程，从而导致北半球平流层N2O、O3、CH4、H2O等微量气体成分的垂直、水平分布发生显著变化；⑤增温过程中活跃的行星波可以造成平流层Brewer-Dobson环流增强，同时导致高纬度地区（60～90°N）穿越对流层顸的臭氧通量（Cross-Tropopause Ozone Flux，CTOF）显著增强，与行星波相联系的等熵物质运动引起“middleworld”区域内向赤道的臭氧通量也有所增强。

In this paper, we analyze the impacts of the stratospheric sudden warming during 2003-2004 winter, on the stratospheric circulation, transportation and ozone flux comprehensively by using the ECWMF data, MIPAS satellite observations and MOZART3 model. In conclusion, we find out that ： （ 1 ） This SSW event is a long and intense process, and causes the stratospheric polar vortex break up from up to low levels. During the establishment of easterlies on 10 hPa altitude, the upper polar vortex recovers promptly. （2） The planetary wave is so active that it transports from troposphere to stratosphere several times and the wave 1 played a major role. （3） The analysis from the 0-PVLAT coordinate reveals that there is a pair of poleward and downward propagating modes in strato-sphere and an equatorward propagating mode in troposphere. Along with these two modes, zonal wind and tempera- ture anomalies transport as two opposite signals. （4） The stratospheric transport is prominently changed by the enhanced poleward transport and the associated variations of the vertical motions during the planetary wave activities. Consequently, the spatial distributions of stratospheric tracers （ N2O, O3 , CH4 and H2O ） are greatly impacted by the warming event. （5） The enhanced wave activities during the warming event have enhanced the Brewer-Dobson circulation in the stratosphere and the cross-tropopause ozone flux in high latitudes. Moreover, the isentropic trans-port associated with the wave enhancement has also increased the meridional ozone flux outside the extratropical ＂middleworld＂ region.