我国上空平流层中微量气体的垂直分布和变化趋势

利用1992～2005年卤素掩星试验（HALOE）的观测资料分析了中国上空平流层的几种微量气体（NO, NO2, HF, HCl, CH4, H2O 和O3）混合比的垂直分布和变化趋势，以期为研究平流层的辐射和化学过程提供一些有用的数据. 文中除给出我国上空平流层各高度上平均的各种微量气体的含量外，还给出青藏高原上空这些微量气体的含量. 分析结果表明，平流层各种微量气体混合比的垂直分布有其不同的特征，在对流层上层到平流层底部各种微量气体的混合比分布和季节变化与平流层相比有明显的差异；分析结果还表明，这些微量气体的季节变化、准两年周期振荡和长期变化趋势都很明显，并且在平流层的不同高度上它们的变化趋势是不相同的. 在平流层中层，NO, NO2, HCl 和H2O 混合比在1998年以前都是增加而后则是明显下降的，但O3相反，在1998年以前明显减少，1998年后其减少的趋势不明显. 这表明，近年来平流层中层这些微量气体的减少使得它们对臭氧的破坏有所缓解. 但在平流层下层，臭氧的耗损仍然很明显.

Contents and trends of the trace gases in the stratosphere over China

In order to provide some useful data for studies on radiative and chemical processes in the stratosphere,the vertical distribution of trace gases(NO,NO-2,HCl,HF,CH-4,H-2O and O-3) and their variation trends in the stratosphere over China have been analyzed by using the HALOE data from 1992 to 2005.Besides the mixing ratio of the traces averaged over China,the values averaged over the Qinghai-Xizang Plateau are also given. The analyses show that the mixing ratios for various trace gases are distributed vertically in different patterns in the stratosphere,the distribution and seasonal variations of the traces near the tropopause are much different from those in the stratosphere.The analyses also show that the seasonal variations,the quasi-biennial oscillation(QBO) signals and the long-term trends are clear for all the traces,and the trends of the trace gases in various levels of the stratosphere are different.In the middle stratosphere,the mixing ratios of NO,NO-2,HCl and H-2O all increased before 1998 and then decreased after 1998,while it is contrary for mixing ratio of O-3 which decreased evidently before 1998 and the decrease trend was not significant after 1998.That means the decrease of those traces lead to the ozone depletion retarded in middle stratosphere in recent years.While in the lower stratosphere,the ozone depletion is still significant.