Exploring the nature of air quality over southwestern Ontario: main findings from the Border Air Quality and Meteorology Study
Exploring the nature of air quality over southwestern Ontario: main findings from the Border Air Quality and Meteorology Study
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探索安大略省西南部空气质量的性质：边境空气质量和气象研究的主要发现
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发表时间：
2013
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通讯作者：
Robert McLaren
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作者：
Jeffrey R. Brook;P. Makar;D. Sills;K. Hayden;Robert McLaren
抽象。本文作为一个概述，并讨论了边境空气质量和气象研究（BAQS-Met）在西南部安大略在2007年的主要结果。该地区以五大湖为主，与美国接壤，并且一直是加拿大臭氧（O3）和细颗粒物浓度最高的地区。BAQS-Met的目的是提高我们对湖泊驱动的气象学如何影响该地区空气质量的理解，并改进用于预测和政策情景的模型。结果表明，湖风发生的频率和内陆渗透距离显着大于过去的认识。由于其对当地气象的影响，湖泊被发现增加二次O3和气溶胶的形成，使当地人为排放的影响更接近人口稠密的源区，而不是在没有湖泊的情况下。观察到O3的空间异质性很大，局部峰值通常高于区域值30 ppb。硫酸盐和二次有机气溶胶（SOA）的增强也与当地的排放量在湖风环流中输送。这项研究包括对五大湖地区高分辨率（2.5公里网格）空气质量模式的区域应用进行的第一次详细评价。该模型表明，二次污染物的最大值发生在收敛的地区，在局部上升气流和在不同的口袋在湖面。这些影响是由湖泊环流与天气流相互作用，彼此或与城市热岛引起的环流。生物和人为排放都显示出在该区域形成SOA的过程中发挥了作用。详细的颗粒测量和多变量受体模型表明，虽然单个颗粒是内部混合的，但它们往往存在于更复杂的外部混合物中。这使得很难预测气溶胶光学特性，并进一步突出了气溶胶建模面临的挑战。BAQS-Met的研究使人们更好地了解了高分辨率（2.5公里）模型对空气质量和气象预测的价值，并使模型得到了若干改进。
Abstract. This paper serves as an overview and discusses the main findings from the Border Air Quality and Meteorology Study (BAQS-Met) in southwestern Ontario in 2007. This region is dominated by the Great Lakes, shares borders with the United States and consistently experiences the highest ozone (O3) and fine particulate matter concentrations in Canada. The purpose of BAQS-Met was to improve our understanding of how lake-driven meteorology impacts air quality in the region, and to improve models used for forecasting and policy scenarios. Results show that lake breeze occurrence frequencies and inland penetration distances were significantly greater than realized in the past. Due to their effect on local meteorology, the lakes were found to enhance secondary O3 and aerosol formation such that local anthropogenic emissions have their impact closer to the populated source areas than would otherwise occur in the absence of the lakes. Substantial spatial heterogeneity in O3 was observed with local peaks typically 30 ppb above the regional values. Sulfate and secondary organic aerosol (SOA) enhancements were also linked to local emissions being transported in the lake breeze circulations. This study included the first detailed evaluation of regional applications of a high-resolution (2.5 km grid) air quality model in the Great Lakes region. The model showed that maxima in secondary pollutants occur in areas of convergence, in localized updrafts and in distinct pockets over the lake surfaces. These effects are caused by lake circulations interacting with the synoptic flow, with each other or with circulations induced by urban heat islands. Biogenic and anthropogenic emissions were both shown to play a role in the formation of SOA in the region. Detailed particle measurements and multivariate receptor models reveal that while individual particles are internally mixed, they often exist within more complex external mixtures. This makes it difficult to predict aerosol optical properties and further highlights the challenges facing aerosol modelling. The BAQS-Met study has led to a better understanding of the value of high-resolution (2.5 km) modelling for air quality and meteorological predictions and has led to several model improvements.