Street Versus Rooftop Level Concentrations of Fine Particles in a Cambridge Street Canyon
Street Versus Rooftop Level Concentrations of Fine Particles in a Cambridge Street Canyon
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剑桥街峡谷中街道与屋顶水平的细颗粒浓度
DOI：
10.1007/s10546-008-9300-3
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发表时间：
2009
影响因子：
4.3
通讯作者：
R. Britter
中科院分区：
文献类型：
--
作者：
Prashant Kumar;P. Fennell;A. Hayhurst;R. Britter
在城市街道峡谷中，颗粒物的数量分布（PND）和浓度（PNC）的变化证明了颗粒物的分散，仍然没有得到很好的理解。本研究比较了测量的快速响应粒子光谱仪（DMS 500）的PND和PNCs（5-1000 nm，采样频率为1 Hz）在街道和屋顶的水平在剑桥英国街道峡谷，并检查混合，物理和化学的转换过程，以及交通量和屋顶风速的PND和PNCs在各种尺寸范围内的竞争影响。街道水平的PNC是屋顶水平的2.65倍。街道水平的PNC跟随交通量，并随着风速的增加而减小，显示风速对30-300 nm颗粒物的影响大于对5-30 nm颗粒物的影响。相反，屋顶PNC在5-30 nm的尺寸范围内增加风速，而30和300 nm之间的颗粒不随风速而变化。
Dispersion of particles, as evidenced by changes in their number distributions (PNDs) and concentrations (PNCs), in urban street canyons, is still not well understood. This study compares measurements by a fast-response particle spectrometer (DMS500) of the PNDs and the PNCs (5–1000 nm, sampled at 1 Hz) at street and rooftop levels in a Cambridge UK street canyon, and examines mixing, physical and chemical conversion processes, and the competing influences of traffic volume and rooftop wind speed on the PNDs and the PNCs in various size ranges. PNCs at street level were ≈6.5 times higher than at rooftop. Street-level PNCs followed the traffic volume and decreased with increasing wind speed, showing a larger influence of wind speed on 30–300 nm particles than on 5–30 nm particles. Conversely, rooftop PNCs in the 5–30 nm size range increased with wind speed, whereas those for particles between 30 and 300 nm did not vary with wind speed.