Alföldy B, Osán J, Tóth Z, Török S, Harbusch A, Jahn C, Emeis S, Schäfer K
Hungarian Academy of Sciences, KFKI Atomic Energy Research Institute, Budapest, Hungary.
Sci Total Environ. 2007 Sep 20;383(1-3):141-63. doi: 10.1016/j.scitotenv.2007.04.037. Epub 2007 Jun 13.
The dependence of aerosol optical depth (AOD) on air particulate concentrations in the mixing layer height (MLH) was studied in Budapest in July 2003 and January 2004. During the campaigns gaseous (CO, SO(2), NO(x), O(3)), solid components (PM(2.5), PM(10)), as well as ionic species (ammonium, sulfate and nitrate) were measured at several urban and suburban sites. Additional data were collected from the Budapest air quality monitoring network. AOD was measured by a ground-based sun photometer. The mixing layer height and other common meteorological parameters were recorded. A linear relationship was found between the AOD and the columnar aerosol burden; the best linear fit (R(2)=0.96) was obtained for the secondary sulfate aerosol due to its mostly homogeneous spatial distribution and its optically active size range. The linear relationship is less pronounced for the PM(2.5) and PM(10) fractions since local emissions are very heterogeneous in time and space. The results indicate the importance of the mixing layer height in determining pollutant concentrations. During the winter campaign, when the boundary layer decreases to levels in between the altitudes of the sampling stations, measured concentrations showed significant differences due to different local sources and long-range transport. In the MLH time series unexpected nocturnal peaks were observed. The nocturnal increase of the MLH coincided with decreasing concentrations of all pollutants except for ozone; the ozone concentration increase indicates nocturnal vertical mixing between different air layers.
2003年7月和2004年1月在布达佩斯研究了混合层高度（MLH）中气溶胶光学厚度（AOD）对空气颗粒物浓度的依赖性。在这些活动期间，在几个城市和郊区站点测量了气态物质（CO、SO₂、NOₓ、O₃）、固体成分（PM₂.₅、PM₁₀）以及离子种类（铵、硫酸盐和硝酸盐）。从布达佩斯空气质量监测网络收集了额外的数据。通过地基太阳光度计测量AOD。记录了混合层高度和其他常见气象参数。发现AOD与柱状气溶胶负荷之间存在线性关系；由于二次硫酸盐气溶胶的空间分布大多均匀且其光学活性粒径范围，因此对其获得了最佳线性拟合（R² = 0.96）。对于PM₂.₅和PM₁₀部分，线性关系不太明显，因为局部排放随时间和空间变化非常不均匀。结果表明混合层高度在确定污染物浓度方面的重要性。在冬季活动期间，当边界层降低到采样站高度之间的水平时，由于不同的本地源和长距离传输，测量浓度显示出显著差异。在MLH时间序列中观察到意外的夜间峰值。MLH的夜间增加与除臭氧外所有污染物浓度的降低同时发生；臭氧浓度的增加表明不同气层之间的夜间垂直混合。
