River winds and pollutant recirculation near the Manaus city in the central Amazon
River winds and pollutant recirculation near the Manaus city in the central Amazon
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DOI：
10.1038/s43247-021-00277-6
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发表时间：
2021-10
影响因子：
7.9
通讯作者：
Tianning Zhao;Jianhuai Ye;I. Ribeiro;Yongjing Ma;H. Hung;Carla E. Batista;Matthew P. Stewart;Patricia Guimarães;J. Vilà‐Guerau de Arellano;R. D. de Souza;A. Guenther;S. Martin
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文献类型：
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作者：
Tianning Zhao;Jianhuai Ye;I. Ribeiro;Yongjing Ma;H. Hung;Carla E. Batista;Matthew P. Stewart;Patricia Guimarães;J. Vilà‐Guerau de Arellano;R. D. de Souza;A. Guenther;S. Martin
由宽阔的亚马逊河和邻近森林之间的热对比引起的当地大气再循环流量（即河流风）可能影响污染物的扩散，但缺乏调查这种可能性的观测平台。在2019年旱季，我们使用直升机型无人机收集了气象变量的日间垂直剖面和高达500米的化学浓度。聚类分析表明，56个剖面中有13个（23%）发生了河-林再循环。在天气晴朗时，当天气风速低于4 m s - 1时，热力驱动的河风充分发展，在此期间一氧化碳和总氧化剂（定义为臭氧和二氧化氮）的垂直剖面发生改变。数值模拟表明，河风可以将污染再循环回河岸。这对整个巴西北部河流沿岸的许多人类住区的空气质量都有影响。
Local atmospheric recirculation flows (i.e., river winds) induced by thermal contrast between wide Amazon rivers and adjacent forests could affect pollutant dispersion, but observational platforms for investigating this possibility have been lacking. Here we collected daytime vertical profiles of meteorological variables and chemical concentrations up to 500 m with a copter-type unmanned aerial vehicle during the 2019 dry season. Cluster analysis showed that a river-forest recirculation flow occurred for 23% (13 of 56) of the profiles. In fair weather, the thermally driven river winds fully developed for synoptic wind speeds below 4 m s−1, and during these periods the vertical profiles of carbon monoxide and total oxidants (defined as ozone and nitrogen dioxide) were altered. Numerical modeling shows that the river winds can recirculate pollution back toward the riverbank. There are implications regarding air quality for the many human settlements along the rivers throughout northern Brazil.