瓦里关山大气甲烷本底浓度变化特征的分析

用气相色谱法在瓦里关全球基准站进行了大气甲烷（CH4）的连续测量，结合NOAA/CMDL气瓶采样CH4浓度资料的分析结果，给出了我国内陆高原大气CH4本底浓度的变化特征。分析结果表明:瓦里关山大气CH4浓度在1780×10-9～1840×10-9范围内波动，浓度值的变化范围符合中高纬度地区CH4浓度分布；CH4浓度有明显的日变化,夏季的变化趋势及振幅与冬春季有所不同；季节变化幅度不大，与全球大气CH4浓度本底值季节变化的特征及变化幅度的地理分布不太一致；有明显的年际变化，CH4年平均浓度表现为逐年升高，年

Characteristics of Atmospheric Methane Concentration Variation At Mt. Waliguan

By using gas chromatographic method, in-situ atmospheric CH4 was measured continuously at China Global Atmosphere Watch Baseline Observatory at Mt. Waliguan. Combining with FLASK CH4 data obtained from NOAA/CMDL, the variation features of atmospheric background CH4 concentration in the inland plateau of China are presented. The results show that the CH4 concentration at Mt. Waliguan are in the range of 1780×10－ 9 ~ 1840×10－ 9, it is in accord with the CH4 distribution in the area of mid and high latitudes. CH4 concentration at Mt. Waliguan has evident diurnal fluctuation, its pattern and amplitude in summer are different from those in winter and spring; there appears no obvious seasonal variation, and it is dissimilar to the feature of seasonal variation and to the geographical distribution of variation amplitude for global atmospheric CH4 background concentration. The results also show that there are distinct interannual variations. CH4 mean annual concentration increases with years and the variations of annual growing rate correspond with the trend of mean variation for atmospheric CH4 in the Northern Hemisphere.