PDF(Pubmed)
Abstract：
New particle formation (NPF) is a major source of atmospheric aerosol particles, including cloud condensation nuclei (CCN), by number globally. Previous research has highlighted that NPF is less frequent but more intense at roadsides compared to urban background. Here, we closely examine NPF at both background and roadside sites in urban Central Europe. We show that the concentration of oxygenated organic molecules (OOMs) is greater at the roadside, and the condensation of OOMs along with sulfuric acid onto new particles is sufficient to explain the growth at both sites. We identify a hitherto unreported traffic-related OOM source contributing 29% and 16% to total OOMs at the roadside and background, respectively. Critically, this hitherto undiscovered OOM source is an essential component of urban NPF. Without their contribution to growth rates and the subsequent enhancements to particle survival, the number of >50 nm particles produced by NPF would be reduced by a factor of 21 at the roadside site. Reductions to hydrocarbon emissions from road traffic may thereby reduce particle numbers and CCN counts.
摘要：
新粒子形成(NPF)是大气气溶胶粒子的主要来源,包括云凝结核(CCN)，按全球数字。先前的研究强调，与城市背景相比，NPF在路边的频率较低，但强度更高。这里,我们仔细检查了中欧城市背景和路边的NPF。我们表明，氧化有机分子（OOMs）的浓度在路边更大，OOMs与硫酸冷凝到新颗粒上足以解释这两个位置的生长。我们确定了迄今为止未报告的与流量相关的OOM源，在路边和背景的总OOM中占29％和16％，分别。严重的,这种迄今为止尚未发现的OOM源是城市NPF的重要组成部分。没有它们对增长率的贡献和随后对粒子存活的增强，在路边，NPF产生的>50nm颗粒的数量将减少21倍。因此,减少来自道路交通的碳氢化合物排放可以减少颗粒数量和CCN计数。
