中文摘要：

利用北京地区上甸子站气溶胶散射系数、PM2.5质量浓度和气象要素1 a的观测资料,研究不同天气条件下上甸子地区散射系数的变化特征,并讨论了气象条件对散射系数的影响.结果表明,散射系数在雾霾天最高608.4 Mm-1,其次为雾天500.6 Mm-1和霾天423.7 Mm-1,是一般天气散射系数的6.4～9.2倍.在各类天气中散射系数均在夏季最高,雾天和雾霾天分别是秋、冬季最低,霾天和一般天气中其他3个季节相差不大.PM2.5的质量散射效率在雾天和雾霾天较高,且雾天的季节变化最明显.散射系数在雾霾天和一般天气中分别呈＂单峰型＂和＂双峰型＂的日变化特征.上甸子地区气溶胶散射系数受地面风的影响显著,在雾霾等低能见度天气中,强西南风对气溶胶的输送是造成上甸子及区域内散射系数水平较高的主要原因,偏东北方向的风有利于散射系数的降低,这种作用在一般天气中表现最为显著.

英文摘要：

A study on the effect of weather condition on the aerosol scattering property has been carried out using one year measurement data sets of aerosol scattering coefficient（ASC） and meteorological parameters at Shangdianzi（SDZ）.The results showed that the ASC was highest in haze-fog day with 608.4 Mm-1 and higher in fog day with 500.6 Mm-1 and haze day with 423.7 Mm-1 those were 6.4-9.2 times higher than the ASC in normal day.The ASC was highest in summer in all kinds of weather conditions.The lower ASC in fog day and haze-fog day was observed in autumn and winter,respectively.There was no evident difference of the ASC between other three seasons in haze day and normal day.Pronounced seasonal variation of the mass scattering efficiency（MSE） of PM2.5 was observed in fog day with the highest value in summer.Significant diurnal variations in ASC were observed in haze-fog day and normal day with a unimodal pattern and a bimodal pattern,respectively.The wind was the most important factor for the ASC at SDZ.The transport of aerosol particles by the strong southwest wind should be responsible for the higher level of ASC in SDZ area and regional scale in low visibility weather conditions.The northeast wind was favourable to the reduction of ASC,especially in normal day.