利用天顶散射光观测反演大气臭氧柱浓度

The Retrieval of Atmospheric Ozone Column Densities using Zenith-sky Scattered Light Observations

利用天顶散射光-差分光学吸收光谱法反演了2006年12月至2007年12月上海地区(31.3°N,121.5°E)上空的臭氧柱浓度.在反演过程中,考虑了O3,NO2,O4,H2O的吸收以及大气Ring效应对测量光谱的贡献.利用经验函数对反演结果进行筛选,将Langley plot方法与O4,H2O的拟合结果相结合,确定参考光谱中的臭氧含量.数据分析表明,2007年上海上空臭氧柱总量高值出现在4月至6月,低值出现在10月至1月,月均值的变化幅度约为50DU.实验测量误差在6%～7%左右.将地基臭氧柱总量观测结果与美国TOMS臭氧观测资料进行对比,二者的变化趋势基本一致,相关系数为0.81,地基观测结果普遍低于TOMS臭氧观测值.最后对二者产生差别的原因进行分析和讨论.

The twilight ozone column densities in Shanghai were deduced using Zenith-sky Scattered Light-Differential Optical Absorption Spectroscopy method. Considering the absorption of O3, NO2,O4, H2O and the Ring effect, ozone slant column densities were retrieved by the least-square fitting method. With an empirical function to filter data, the amount of ozone in the reference Frannhofer spectrum was deduced by combining the Langley plot method with the retrieved O4 and H2O slant column densities. The derived ozone columns at twilight from Dec. 19,2006 to Dec. , 2007 were presented, which showed the annual evolution of ozone total column densities with high level in spring（Apr, to Jun. ）and low level in autumn and winter（Oct, to Jan. ）. The variation of monthly-averaged ozone total columns was about 50 DU. The accuracy of the results was about 6 % - 7 %. The comparison between ground-based and TOMS ozone vertical column densities showed good agreement,with the correlative coefficient about 0.81. The TOMS ozone total column densities were several percents higher than the ground-based measurement results. Reasons accounting for this bias were discussed.