Impact of Urban Pollution on Organic-Mediated New-Particle Formation and Particle Number Concentration in the Amazon Rainforest.
Impact of Urban Pollution on Organic-Mediated New-Particle Formation and Particle Number Concentration in the Amazon Rainforest.
复制标题
城市污染对亚马逊雨林中有机介导的新颗粒形成和颗粒数量浓度的影响。
DOI：
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发表时间：
2021
影响因子：
11.4
通讯作者：
B. Gaudet
中科院分区：
文献类型：
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作者：
Bin Zhao;J. Fast;N. Donahue;M. Shrivastava;Meredith Schervish;J. Shilling;H. Gordon;Jian Wang;Yang Gao;R. Zaveri;Y. Liu;B. Gaudet
评估气溶胶对气候变化的影响的一个主要挑战是了解人类活动如何改变相对于原始/工业化前基线的气溶胶载量和性质。在这里，我们结合化学传输模拟和现场测量来研究来自一个孤立的大都市的人为污染通过各种新粒子形成(NPF)机制和初级粒子排放对前工业化亚马逊雨林上空颗粒物数量浓度的影响。为了表示有机介导的NPF，我们采用了一个最先进的模型，该模型系统地模拟了极低挥发性有机化合物的形成化学和热力学，以及它们在NPF过程中的作用，并进一步更新了模型，以改进人类影响条件下的有机NPF模拟。结果表明，与背景条件相比，城市污染使下风区(距市中心200公里以内)的颗粒物浓度增加了5-25倍。我们的模式表明，除紧邻震源外，NPF对下风区粒子总数的贡献率超过70%。在不同的NPF机理中，涉及有机物和硫酸的三元NPF占压倒性优势。对粒子形成机制的更好理解将有助于更好地量化从前工业化时代到现在的人为气溶胶强迫。
A major challenge in assessing the impact of aerosols on climate change is to understand how human activities change aerosol loading and properties relative to the pristine/preindustrial baseline. Here, we combine chemical transport simulations and field measurements to investigate the effect of anthropogenic pollution from an isolated metropolis on the particle number concentration over the preindustrial-like Amazon rainforest through various new-particle formation (NPF) mechanisms and primary particle emissions. To represent organic-mediated NPF, we employ a state-of-the-art model that systematically simulates the formation chemistry and thermodynamics of extremely low volatility organic compounds, as well as their roles in NPF processes, and further update the model to improve organic NPF simulations under human-influenced conditions. Results show that urban pollution from the metropolis increases the particle number concentration by a factor of 5-25 over the downwind region (within 200 km from the city center) compared to background conditions. Our model indicates that NPF contributes over 70% of the total particle number in the downwind region except immediately adjacent to the sources. Among different NPF mechanisms, the ternary NPF involving organics and sulfuric acid overwhelmingly dominates. The improved understanding of particle formation mechanisms will help better quantify anthropogenic aerosol forcing from preindustrial times to the present day.