摘要
该研究利用在成都市3个点位开展的为期1年(2013年9月-2014年8月)的连续监测数据和收集的气象观测数据,分析成都市大气能见度的主要影响因素。利用IMPROVE公式对消光系数进行重建,识别影响能见度的主要PM_(2.5)组分。研究结果表明:观测期间成都大气能见度水平整体较差,年平均值为8.3 km,8月最高,1月最低;PM_(2.5)和SNA(NH_4^+、NO_3^-、SO_4^(2-)的简称)与VIS呈非线性关系,且VIS与SNA的负相关性最好。硫酸盐对消光的贡献最大(34.8%),其次是硝酸盐(26.3%)。夏季能见度水平主要受硫酸盐的影响,冬季能见度水平的显著降低主要是硫酸盐、硝酸盐和有机物的共同作用。二次粒子是造成极低能见度现象的主要PM_(2.5)组分,尤其是硝酸盐的贡献导致能见度下降明显。进一步加强对燃煤和机动车的控制才能有效缓解大气能见度下降的问题。
The data set used in this study include three-sites continuous PM_(2.5) components sampling data in Chengdu for 1 year(September 2013-August 2014) and meteorological data. To identify the main components affecting visibility, IM-PROVE formula is used to reconstruct extinction coefficient. The results show: visibility in Chengdu is poor, and annual aver-age is only 8.3 km, highest in August and lowest in January. PM_(2.5) and SNA have nonlinear relationship with VIS, and VIS have best negative correlation with SNA. Sulfate contributes the most to extinction coefficient(34.8 %), followed by nitrate(26.3%). Visibility level is mainly affected by sulfate in summer, while sulfate, nitrate and organic matter are joint contributors to the low visibility in winter. Secondary particles are the main components of PM_(2.5) causing low visibility phenomenon, especially nitrate. To further strengthen the control of coals and motor vehicles can effectively solve the problem of decrease of visibility.
出处
《环境科学与技术》
CAS
CSCD
北大核心
2017年第S2期211-215,共5页
Environmental Science & Technology
