安徽省寿县气溶胶消光系数变化特征分析

基于自主研发的气溶胶消光光谱仪, 在安徽省寿县观测站点进行了连续观测, 并对 2016 年 5 月至 12 月期间该地区的大气气溶胶光学特性开展了研究。结合不同大气因素分析了观测结果的时间序列变化及日变化规律, 对比了消光系数与 PM2.5 质量浓度、散射系数的相关性, 并探讨了风速风向对于寿县消光系数变化的影响。结果表明: 寿县地区大气消光系数时间序列变化与日变化特征明显, 且受到不同气象要素的影响。秋季和冬季的大气污染情况较为严重, 与其他季节相比, 污染天气的天数明显增多; 与清洁天气相比, 污染天气的消光系数和 PM2.5 质量浓度、散射系数显著增大。特别在冬季, 污染事件频繁。在 12 月份出现过重度污染天, 其 24 h PM2.5 平均浓度超过 150 µg·m−3,且该月消光系数和 PM2.5 质量浓度、散射系数均达到观测期间月平均最大值。整个观测期间, 从日变化来看, 消光系数、PM2.5 质量浓度及散射系数均是白天波动较大, 午后出现最低值; 其中消光系数最大值出现于清晨 08:00 左右, 最小值则出现于下午 16:00 左右。此外, 消光光谱仪测得的气溶胶消光系数与 PM2.5 质量浓度和散射系数的相关系数分别为 0.91 和 0.83, 说明研制的消光光谱仪同其他仪器的测量结果具有很好的一致性。

Variation characteristics of aerosol extinction coefficient inShouxian,Anhui Province

Based on the self-developed aerosol extinction spectrometer, continuous observation was carried out atShouxian Observation Station in Anhui Province, China, and the aerosol optical properties in this area from May to December 2016 were studied. Combined with the different atmospheric factors, the time series change and daily change law of observation results were analyzed, the correlation between extinction coefficient and PM2.5 massconcentration, scattering coefficient were compared, and the influence of wind speed and direction on the variationof extinction coefficient in Shouxian was discussed. The results show that the time series and diurnal variationcharacteristics of atmospheric extinction coefficient in Shouxian area are obvious, and they are affected by differentmeteorological factors. Compared with other seasons, the air pollution in autumn and winter is more serious, and thenumber of days of polluted weather is increased significantly. Compared with clean weather, the extinction coefficient, PM2.5 mass concentration and scattering coefficient of polluted weather are increased significantly. Especiallyin winter, pollution events are more frequent. For example, in December, the average concentration of PM2.5 in24 h exceeds 150 µg·m−3, and the extinction coefficient, PM2.5 mass concentration and scattering coefficient of themonth reach the monthly average maximum value during the observation period. During the observation period,according to the diurnal variation, the extinction coefficient, PM2.5 mass concentration and scattering coefficientfluctuate greatly in the daytime, and the lowest values appear in the afternoon. The maximum extinction coefficient appears at about 08:00 a.m., and the minimum value appears at about 16:00 p.m.. In addition, the correlationcoefficients of aerosol extinction coefficient measured by extinction spectrometer with PM2.5 concentration and scattering coefficient are 0.91 and 0.83, respectively, indicating that the measurement results of the developed extinctionspectrometer are in good agreement with those of other instruments.