张掖地区春季大气气溶胶的光学特性

利用2008年4-6月份张掖气候观象台CE-318的观测资料,结合同期PM₁₀质量浓度和地面常规气象资料,分析了气溶胶光学厚度AOD,Angstrom指数和PM₁₀质量浓度的时间变化特征,讨论了AOD与气象要素的关系以及AOD与PM₁₀质量浓度的相关性.结果表明,观测期间AOD与浑浊度系数β的日均值变化趋势较为一致,与波长指数α呈较弱的负相关.AOD大致存在四种日变化形式:1)平缓稳定;2)早晚低,中午较高;3)早晨低,傍晚高;4)早晨高,傍晚低.观测点受西北（偏北）风控制时,AOD易出现较高值,相对湿度的变化对AOD大小影响不明显.日平均情况下AOD和PM₁₀质量浓度的相关系数R²为0.735 9,大于小时平均情况下的0.4035.

Observational study on aerosol optical characteristics over Zhangye during springtime of 2008

Atmospheric aerosol optical depth（AOD） and the Angstrom parameter were derived from the measurement of CE-318 automatic sun tracking spectrophotometer at Zhangye Climate Observatory from April to June,2008,and in combination with the mass concentration of PM₁₀ data and the routine weather observation data,a comprehensive analysis was conducted.The time change characteristics of AOD,the Angstrom parameter and the mass concentration of PM₁₀ also were analyzed.The relationship between AOD and meteorological parameter,and the correlation between AOD and mass concentration of PM₁₀ were also discussed.It was found that AOD and the turbidity coefficient had the same variation trend in daily means and the correlation between AOD and wavelength exponent was weakly negative.AOD had four patterns of diurnal variations in the observation period:1) AOD varied gently;2) AOD peaked at noon;3) AOD was low in the morning and high in the evening;4) AOD was high in the morning and low in the evening.The correlation between AOD and the relative humidity was not obvious and,when the northwest（northerly） wind was prevailing,AOD tended to have a higher value.The correlation coefficient between AOD and mass concentration of PM₁₀ in daily means was 0.735 9,larger than 0.403 5 which was the correlation coefficient in hourly means.