Urban aerosol chemistry at a land–water transition site during summer – Part 1: Impact of agricultural and industrial ammonia emissions
Urban aerosol chemistry at a land–water transition site during summer – Part 1: Impact of agricultural and industrial ammonia emissions
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DOI：
10.5194/acp-21-13051-2021
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发表时间：
2021-09
影响因子：
6.3
通讯作者：
Nicholas Balasus;Michael A. Battaglia Jr.;K. Ball;V. Caicedo;R. Delgado;A. Carlton;C. Hennigan
中科院分区：
文献类型：
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作者：
Nicholas Balasus;Michael A. Battaglia Jr.;K. Ball;V. Caicedo;R. Delgado;A. Carlton;C. Hennigan
抽象。本研究描述了切萨皮克湾和相关气象现象对2018年6月4日至7月5日进行的第二次臭氧水-陆地环境过渡研究（OWLETS-2）实地活动期间气溶胶化学的影响。无机PM2.5组成，气相氨（NH3），和一系列的气象参数的测量进行了在哈特-米勒岛（HMI），陆地-水的过渡站点东部的市中心巴尔的摩的切萨皮克湾。HMI的观测结果显示NH3浓度异常高（最大值为19.3 µg m−3，平均值为3.83 µg m−3），比最近的大气氨监测网络（AMoN）站点（约45公里）测量的NH3浓度高出3倍以上。虽然HMI的硫酸盐浓度与45公里外的监管监测站测得的浓度相当一致，但由于NH3升高导致的富氨条件，气溶胶铵和硝酸盐浓度显着较高。NH3浓度高主要是由于区域农业排放，包括宾夕法尼亚州东南部的奶牛场和德尔马瓦半岛（特拉华州-马里兰州-弗吉尼亚州）的家禽养殖场。减少NH3沉积在运输过程中的切萨皮克湾可能有助于提高浓度在HMI相比，更内陆的AMON网站。记录了几个峰值NH3事件，包括在OWLETS-2期间观察到的最大NH3，这些事件似乎源自巴尔的摩市中心附近的工业源集群。这些事件都与低风速（< 1 m s−1）和稳定大气条件下的夜间排放和对HMI的平流有关。我们的研究结果表明，工业源的重要性，包括几个不代表在排放清单中，对城市空气质量。再加上我们的配套文件，其中检查气溶胶液态水和pH值在OWLETS-2，我们强调了独特的过程影响城市空气质量的沿海城市是不同于大陆的位置。
Abstract. This study characterizes the impact of the Chesapeake Bay and associated meteorological phenomena on aerosol chemistry during the second Ozone Water-Land Environmental Transition Study (OWLETS-2) field campaign, which took place from 4 June to 5 July 2018. Measurements of inorganic PM2.5 composition, gas-phase ammonia (NH3), and an array of meteorological parameters were undertaken at Hart-Miller Island (HMI), a land–water transition site just east of downtown Baltimore on the Chesapeake Bay. The observations at HMI were characterized by abnormally high NH3 concentrations (maximum of 19.3 µg m−3, average of 3.83 µg m−3), which were more than a factor of 3 higher than NH3 levels measured at the closest atmospheric Ammonia Monitoring Network (AMoN) site (approximately 45 km away). While sulfate concentrations at HMI agreed quite well with those measured at a regulatory monitoring station 45 km away, aerosol ammonium and nitrate concentrations were significantly higher, due to the ammonia-rich conditions that resulted from the elevated NH3. The high NH3 concentrations were largely due to regional agricultural emissions, including dairy farms in southeastern Pennsylvania and poultry operations in the Delmarva Peninsula (Delaware–Maryland–Virginia). Reduced NH3 deposition during transport over the Chesapeake Bay likely contributed to enhanced concentrations at HMI compared to the more inland AMoN site. Several peak NH3 events were recorded, including the maximum NH3 observed during OWLETS-2, that appear to originate from a cluster of industrial sources near downtown Baltimore. Such events were all associated with nighttime emissions and advection to HMI under low wind speeds (< 1 m s−1) and stable atmospheric conditions. Our results demonstrate the importance of industrial sources, including several that are not represented in the emissions inventory, on urban air quality. Together with our companion paper, which examines aerosol liquid water and pH during OWLETS-2, we highlight unique processes affecting urban air quality of coastal cities that are distinct from continental locations.