Sources and contributions of wood smoke during winter in London: assessing local and regional influences
Sources and contributions of wood smoke during winter in London: assessing local and regional influences
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DOI：
10.5194/acp-15-3149-2015
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发表时间：
2014-05
影响因子：
6.3
通讯作者：
L. Crilley;W. Bloss;J. Yin;D. Beddows;R. Harrison;J. Allan;D. Young;M. Flynn;P. Williams;P. Zotter;A. Prévôt;M. Heal;J. Barlow;C. Halios;James D. Lee;S. Szidat;C. Mohr
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文献类型：
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作者：
L. Crilley;W. Bloss;J. Yin;D. Beddows;R. Harrison;J. Allan;D. Young;M. Flynn;P. Williams;P. Zotter;A. Prévôt;M. Heal;J. Barlow;C. Halios;James D. Lee;S. Szidat;C. Mohr
抽象的。由于城市地区家庭供暖性质的变化，确定木材烟雾对伦敦等大城市空气污染的贡献变得越来越重要。在冬季，生物质燃烧排放已被确定为欧洲空气质量限制的主要原因。这项工作的目的是量化伦敦生物质燃烧对PM2.5浓度的贡献，并确定本地排放或区域贡献是否是生物质烟雾的主要来源。为了实现这一目标，一些生物质燃烧化学示踪剂进行了分析，在伦敦市中心的一个网站和两个网站在周围的农村地区。左旋葡聚糖，元素碳（EC），有机碳（OC）和K+的浓度一般在三个网站之间的相关性很好。在所有的网站，生物质燃烧被认为是OC和EC的来源，EC的最大贡献来自交通排放，而OC的主要部分包括二次有机气溶胶，主要生物源和烹饪源的贡献。根据与14 C分析得出的估计值的比较，发现EC和OC的源解析可以合理估计非化石和化石燃料源的总碳。来自蒸散计的黑碳数据也被分配到生物质燃烧和交通的贡献，并显示出类似的趋势，观察到的EC。在2012年1月至2月的活动期间，这些地点的平均木材烟雾量估计为0.78至1.0微克/立方米。在伦敦一座160米高的塔上进行的测量表明，在区域和伦敦的空气中，棕色碳与黑色碳的比例相似（分别反映了木材燃烧和交通）。观察到左旋葡聚糖和K+浓度的峰值与低环境温度相一致，这与伦敦的主要本地来源-家庭供暖相一致。总体而言，生物质烟雾的来源在伦敦的结论是一个背景区域源覆盖的贡献，从当地的家庭燃烧排放。这可能会影响到在冬季考虑未来的排放控制策略，并可能是未来工作的重点，以更好地确定贡献的本地源。
Abstract. Determining the contribution of wood smoke to air pollution in large cities such as London is becoming increasingly important due to the changing nature of domestic heating in urban areas. During winter, biomass burning emissions have been identified as a major cause of exceedances of European air quality limits. The aim of this work was to quantify the contribution of biomass burning in London to concentrations of PM2.5 and determine whether local emissions or regional contributions were the main source of biomass smoke. To achieve this, a number of biomass burning chemical tracers were analysed at a site within central London and two sites in surrounding rural areas. Concentrations of levoglucosan, elemental carbon (EC), organic carbon (OC) and K+ were generally well correlated across the three sites. At all the sites, biomass burning was found to be a source of OC and EC, with the largest contribution of EC from traffic emissions, while for OC the dominant fraction included contributions from secondary organic aerosols, primary biogenic and cooking sources. Source apportionment of the EC and OC was found to give reasonable estimation of the total carbon from non-fossil and fossil fuel sources based upon comparison with estimates derived from 14C analysis. Aethalometer-derived black carbon data were also apportioned into the contributions from biomass burning and traffic and showed trends similar to those observed for EC. Mean wood smoke mass at the sites was estimated to range from 0.78 to 1.0 μg m−3 during the campaign in January–February 2012. Measurements on a 160 m tower in London suggested a similar ratio of brown to black carbon (reflecting wood burning and traffic respectively) in regional and London air. Peaks in the levoglucosan and K+ concentrations were observed to coincide with low ambient temperature, consistent with domestic heating as a major contributing local source in London. Overall, the source of biomass smoke in London was concluded to be a background regional source overlaid by contributions from local domestic burning emissions. This could have implications when considering future emission control strategies during winter and may be the focus of future work in order to better determine the contributing local sources.