整层大气甲烷总量季节变化的遥测

REMOTE SENSING OF SEASONAL VARIATION IN COLUMN ABUNDANCE OF ATMOSPHERIC CH_4

利用自行研制的一台用于探测大气成分的太阳红外光谱仪 ,在地面连续自动地记录了晴天的太阳红外光谱。用逐线积分法计算了整层大气的吸收 ,发现在 3.42 8μm波段主要是大气甲烷的吸收 ,从记录的该波段的太阳红外光谱中反演出整层大气中甲烷的总含量 ,经过近一年半的观测 ,得到了合肥地区大气甲烷垂直柱含量的季节变化规律。发现其变化规律与北半球背景对流层空气采样分析法测量的甲烷季节变化规律基本相同。文中详细介绍了测量仪器、测量原理和部分测量结果 ,并对结果进行了简单的讨论。

Infrared solar spectra on clear days were measured automatically by an infrared solar spectrometer (ISS) with 0.4 cm -1 resolution developed by us. A line by line (LBL) computation method was used to calculate theoretical atmospheric absorption. In the wavelength range of 3.410-3.438 μm, the absorption is mainly due to atmospheric methane and water vapor. Column atmospheric methane was retrieved from the recorded infrared solar spectra. The seasonal variation of column atmospheric methane in Hefei was obtained from the measuremental data of nearly 18 months since April of 1997, and the seasonal variation was found to be similar to that of background data. The instruments, principles of measurement and some of results were introduced, and the results are also discussed briefly in the paper.