基于MLS卫星临边探测数据研究大气OH时空分布

 OH自由基是大气中重要的氧化剂,对大气中其他气体成分和气溶胶的形成和转化起着重要作用。本文利用MLS(micro-wave limb sounder)卫星观测资料,对大气平流层上层和中间层OH自由基的时空分布和变化以及中国上空OH自由基的垂直分布进行分析。结果显示,大气平流层上层和中间层OH自由基含量存在明显的季节变化和昼夜变化,在空间上的分布也随着太阳直射点的不同而呈现一定的周期性。比较了中国上空与同纬度纬向平均值,发现白天和夜间的观测值只有个别位置有较明显偏差,中国地区上空的OH含量比在整体上与同纬度比起来无明显异常,中国局地上空廓线的比较更加详细地反映了OH自由基的昼夜垂直结构。总之,中层大气OH自由基含量存在显著的昼夜变化、季节变化,同时也受太阳活动的影响,年际变化则不明显。

Temporal and spatial distributions of atmospheric hydroxyl radicals based on the observation with the aura microwave limb sounder

OH radicals are important oxidants in the atmosphere, and play important roles in the formation and the conversion of other gases and aerosols in the atmosphere. This paper reviews the research progresses of OH radicals at home and abroad. The temporal and spatial distributions and the changes of the upper stratospheric and mesospheric OH radicals are analyzed based on the MLS (microwave limb sounder) satellite data,especially, the vertical distributions of OH radicals over China. It is shown that there are obvious seasonal and diurnal changes of the OH radical volume mixing ratio in the upper stratosphere and the mesosphere. Compared the OH radical volume mixing ratio over China with the zonal mean values of the same latitudes, it is found that the most of the observed volume mixture ratios of the day and the night are similar at the same latitudes, and there is no obvious difference between them. The profiles over some areas of China reflect the detailed vertical distributions of the day and the night. In a word, the diurnal and seasonal variations of the OH radical concentration in the middle atmosphere can obviously seen. The OH radical volume mixture ratio is also affected by the solar activity, and the annual variation is not significant.