广州市与北京市大气能见度与颗粒物质量浓度的关系

为了研究相对湿度(RH)和颗粒物对能见度的影响,于2008年12月11日～2009年8月27日和2008年7月14～2008年9月17日分别在广州和北京对能见度、RH、PM2.5和PM10进行了监测.结果表明,PM2.5和RH是影响能见度的主要因子;在RH≤70%和80%RH≤90%的湿度区段下,2个地区的PM2.5对能见度的影响不同;而在70%RH≤80%湿度区段下,2个地区能见度与颗粒物之间相关性均最好.能见度与PM2.5的拟合曲线在约0.05mg/m3处是一个分界:当PM2.50.05mg/m3时,随着PM2.5降低,能见度变化不明显;当PM2.50.05mg/m3时,随着PM2.5降低,能见度迅速改善.因此,在颗粒物治理的起始阶段,PM2.5下降对能见度的改善效果不很明显;但当PM2.5降低到一定程度后,能见度的改善效果非常显著.

Correlation between the atmospheric visibility and aerosol fine particle concentrations in Guangzhou and Beijing

In order to study the effects of relative humidity (RH) and aerosol fine particles (PM2.5 and PM10) on visibility, visibility, RH, PM2.5 and PM10 during 11th December, 2008~27th August, 2009 in Guangzhou, and 14th July~17th September, 2008 in Beijing were measured, respectively. PM2.5 and RH were the main factors on effecting visibility. When the RH was lower than 70% and between 80% and 90%, the effects of PM2.5 on visibility in Guangzhou and Beijing were different. However, a good correlation between visibility and PM2.5 was found both in Guangzhou and Beijing when RH was between 70% and 80%. A division was found in 0.05mg/m3 from the fitting curve. The visibility did not vary obviously with the PM2.5 concentration reduction when the concentration of PM2.5 was higher than 0.05mg/m3. However, a rapid improving in visibility was observed with decreasing of the PM2.5 concentration when the concentration of PM2.5 was lower than 0.05mg/m3. Therefore, the reduction on PM2.5 did not show obvious improving in visibility at the early time of controlling PM2.5, whereas the visibility could be remarkably improved when the concentration of PM2.5 reduced to a certain value.