辽宁地区大气黑碳气溶胶质量浓度在线连续观测

利用2008年3月—2009年2月辽宁沈阳、大连、鞍山、抚顺和本溪ρ(黑碳)观测资料,分析了其变化特征及重要影响因子.结果表明,5个城市小时ρ(黑碳)的变幅较大,最小值出现在抚顺秋季的2008年9月23日00:00,ρ(黑碳)为0.14μgm3,最大值出现在本溪冬季的2008年11月11日08:00,ρ(黑碳)为64.52μgm3;本溪ρ(黑碳)日均值最高,为6.87μgm3,其次是沈阳、鞍山和抚顺,大连的ρ(黑碳)日均值最小,为3.18μgm3;ρ(黑碳)日变化有明显的峰值和谷值,最高值一般出现在06:00─09:00和17:00─19:00,低值出现在02:00─04:00和12:00─15:00;风速对ρ(黑碳)有重要影响,当风速<3.5 ms时,ρ(黑碳)随风速增大而减小,当风速>3.5 ms时,风速对ρ(黑碳)的影响不大;后向风轨迹较好地反映污染物在不同城市区域间的传输特征,在冬季沈阳以上风区域北部影响为主;ρ(黑碳)日均值变化和大气低层垂直温度梯度变化有较好的对应关系.

In Situ Continuous Observation of Atmospheric Black Carbon Aerosol Mass Concentration in Liaoning Region

The variation characteristics and important influencing factors of black carbon aerosol mass concentrations observed at Shenyang,Dalian,Anshan,Fushun and Benxi Cities of Liaoning Province from March 2008 to February 2009 were analyzed.The results show that the black carbon(BC) mass concentrations had a large variation range among the five cities.The lowest BC hourly mass concentration value of 0.14 μgm3 appeared at 00:00 on September 23,2008,during autumn in Fushun.The highest value of 64.52 μgm3 occurred at 08:00 on November 11,2008,during winter in Benxi.The average BC mass concentration was highest in Benxi,with the value 6.87 μgm3,followed by Shenyang,Anshan and Fushun.The lowest mean mass concentration was in Dalian,with the value 3.18 μgm3.The daily variation of BC mass concentration was characterized by a pronounced double-peak pattern,with peak mass concentrations occurring during 06:00-09:00 and 17:00-19:00,and valley concentrations occurring during 02:00-04:00 and 12:00-15:00.Wind speed had important influence on BC mass concentration.When the wind speed was slow(less than 3.5 ms),there was a dilution effect on BC mass concentration.When the wind speed was faster than 3.5 ms,the relevance was not apparent.The characteristics of air pollution transport and diffusion between different regions were well reflected through the backward wind trajectories.The northern windward regions mostly influenced Shenyang in winter.Vertical temperature gradient variation of the boundary layer atmosphere had a good correlation with daily mean BC mass concentration variation.