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.