HALOE资料揭示的热带平流层CH_4时空变化特征

Temporal and Spatial Features of Tropical Stratospheric CH_4 from the Halogen Occultation Experiment

中层大气微量成分的分布和变化是中层大气研究的重要问题之一,但是长期以来中层大气的资料非常少。卤素掩星试验(HALOE)对中层大气多种微量气体进行观测,形成中层大气多种微量元素的空间分布和时间演变资料组,这是对中层大气微量气体含量资料的极大补充。作者利用1992~2003年HALOE资料分析热带地区(20°S^20°N)平均的CH4的垂直分布和时间演变特征。结果表明:热带平流层CH4混合比在平流层下层有较充分的混合;热带平流层CH4混合比的季节变化明显,在平流层中上层以年循环为主,而在平流层下部以半年变化为主;热带平流层CH4混合比的年际变化主要有准2年和准5年振荡。

Exploring the characteristics of structure and variations of tracers is one of the most important contents of middle atmosphere studies, which are mostly confined by poor data in the middle atmosphere. The Halogen Occultation Experiment （HALOE） has been carried out to measure some key species in the middle atmosphere and formed data sets offer supplies for the data deficiency. HALOE methane data during the period of 1992-2003 are used to analyze the vertical distribution and time variation of tropical stratospheric methane （20°S-20°N） . The resuits indicate that tropical methane mix sufficiently in the lower stratosphere. Tropical methane behaves as annual cycle in the middle-upper stratosphere and as semi-annual cycle in the lower stratosphere. Interannual variability of tropical stratospheric methane act as quasi-biennial and semi-decadal period.