Smoke aerosols emitted by wildfires can ascend to the free troposphere, travel over long distances and descend to affect local air quality (AQ) in downwind areas. This study investigates the AQ impact of long-range transported (LRT) smoke aerosols from western North America during summer 2017 in New York State (NYS) using observations and numerical products. Analysis of total fine particulate matter (PM_2.5) and black carbon measurements at Queens and Buffalo shows that about 38% and 43% of the polluted events are related to the LRT smoke aerosols, respectively. Two LRT smoke events transported from the Pacific Northwest to NYS on Sep. 5 and 16, 2017, are analyzed. The transport path is determined by the large-scale flow (positive tilted trough for the 1st case and stationary front for the 2nd case). During both events, smoke aerosols were entrained into the boundary layer during the growth of the planetary boundary layer (PBL) and accumulated near surface when the PBL collapsed. The enhanced aerosol mass is primarily due to carbonaceous and secondary sulfate aerosols. Although the two events differed in aerosol loadings (150 versus 80 mg m⁻² for column mass density), weather conditions (cold front passage versus high-pressure system), and entrainment rates (6 versus 12 cm s⁻¹), the AQ impacts were comparable for two events (about 10 μg m⁻³ increase of total PM_2.5). Our study of two smoke cases indicates that the LRT smoke events even with moderate intensity would degrade local AQ if the underlying meteorological conditions are favorable for downward mixing.

野火释放的烟雾会上升到对流层，长距离传播并下降，从而影响顺风地区的当地空气质量（AQ）。这项研究使用观测数据和数值产品调查了2017年夏季在纽约州（NYS）从北美西部运来的远程运输（LRT）烟雾气溶胶对AQ的影响。分析总细颗粒物（PM _2.5）和皇后区和布法罗市的黑碳测量表明，分别约有38％和43％的污染事件与LRT烟雾气溶胶有关。分析了2017年9月5日至16日从太平洋西北地区运送到NYS的两次LRT烟雾事件。输送路径由大流量决定（第一种情况下为正倾斜的槽，第二种情况下为静止的前端）。在这两个事件期间，烟雾气溶胶在行星边界层（PBL）的生长过程中被夹带到边界层中，并在PBL塌陷时聚集在地表附近。气溶胶质量的增加主要归因于碳质和仲硫酸盐气溶胶。尽管两个事件的气溶胶载量不同（150 vs 80 mg m ^-2对于色谱柱质量密度），天气条件（冷前通道与高压系统相比）和夹带率（6对12 cm s ^-1），AQ的影响在两个事件中是可比的（总量增加约10μgm ^-3） PM _2.5）。我们对两个烟雾案例的研究表明，如果潜在的气象条件有利于向下混合，即使强度适中的LRT烟雾事件也会降低局部空气质量。