半干旱地区气溶胶散射和吸收特性的观测研究

Observational Studies on Characteristics of Aerosol Scattering and Absorption Coefficients over Semi-Arid Area of China

利用兰州大学半干旱气候和环境观测站SACOL(Semi-Arid Climate and Environment Observatory of Lanzhou University)2007年11月1日-2008年10月31日AE-31黑碳仪和2007年8月1日-2008年7月31日M9003积分浊度仪的连续观测资料,对该地区气溶胶散射和吸收特性的变化特征进行了分析。结果表明,该地区气溶胶年平均散射系数为158.86M.m-1,吸收系数为14.11M.m-1,520nm单次散射比为0.83;散射系数和吸收系数的年变化呈单峰型,峰值分别出现在12月和11月;采暖期内日变化呈双峰型,非采暖期内近似表现为单峰型。在沙尘天气条件下,散射系数和吸收系数分别增大了103.8%和88.5%。结合同期APS-3321粒子谱仪的相关观测资料分析得出,无论是粒子数浓度还是质量浓度,与散射系数和吸收系数的相关系数均在0.8以上。

Based on the continuous observational data by AE-31 from 1 November 2007 to 31 October 2008 and M9003 from 1 August 2007 to 31 July 2008 at Semi-Arid Climate and Environment Observatory of Lanzhou University（SACOL）,the characteristics of aerosol scattering and absorption coefficients were studied over semi-arid area of China.The results show that the annual average scattering coefficient is 158.86 M·m-1,the absorption coefficient is 14.11 M·m-1 and the single scattering albedo at 520 nm is 0.83 over this region.The annual variations of scattering coefficient and the absorption coefficient are single-peak type.The peak values of scattering and absorption coefficients appear in December and November,respectively.The diurnal variations of both coefficients are double-peak during the heating period but single-peak type in the non-heating period.Under the dust weather condition,both the coefficients increase to 103.8% and 88.5%.Utilizing the data from APS-3321 at the same time,the correlation between scattering and absorption coefficients PM2.5 concentration,have been studied,the results show both the coefficients have good relationship with PM2.5 concentration and the correlation coefficients are more than 0.8.