Huiying Xuan, Jun Liu, Yaqi Zhao, Qing Cao, Tianzeng Chen, Yonghong Wang, Zirui Liu, Xu Sun, Hao Li, Peng Zhang, Biwu Chu, Qingxin Ma, Hong He
{"title":"北京秋季雾霾事件中相对湿度驱动的夜间 HONO 形成机制","authors":"Huiying Xuan, Jun Liu, Yaqi Zhao, Qing Cao, Tianzeng Chen, Yonghong Wang, Zirui Liu, Xu Sun, Hao Li, Peng Zhang, Biwu Chu, Qingxin Ma, Hong He","doi":"10.1038/s41612-024-00745-8","DOIUrl":null,"url":null,"abstract":"Nitrous acid (HONO), a key precursor of hydroxyl radicals (OH), is one of the factors affecting atmospheric chemistry and air quality. Currently, the proposed sources of HONO are not able to fully explain observed HONO concentrations. In this study, a comprehensive field observation of HONO was conducted in the autumn of 2021 in urban Beijing. The box model using a default Master Chemical Mechanism (MCM) was unable to reproduce the observed HONO concentrations with a normalized mean bias (NMB) of −92.8%. The NMB improved to −46.1% after the inclusion of seven additional HONO formation pathways. Several factors like vehicle emission factor (1.23%) and nocturnal NO2 heterogeneous uptake coefficient on the ground surface (8.25 × 10−6) were calculated based on observational data. The enhancement factor for nocturnal NO2 heterogeneous conversion was established as a function of relative humidity (RH) and incorporated into the model, which compensated for the missing nocturnal HONO sources and well-reproduced the observed HONO concentrations, with an NMB of −5.1%. The major source of HONO at night was found to be the heterogeneous reaction of NO2 on the ground surface, contributing up to 85.6%. During the daytime, it was the homogeneous reaction of NO with OH, accounting for 41.8%. The daytime primary source of OH was mainly the photolysis of HONO, which constituted 73.6% and therefore promoted the formation of secondary pollutants and exacerbated haze events.","PeriodicalId":19438,"journal":{"name":"npj Climate and Atmospheric Science","volume":null,"pages":null},"PeriodicalIF":8.5000,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41612-024-00745-8.pdf","citationCount":"0","resultStr":"{\"title\":\"Relative humidity driven nocturnal HONO formation mechanism in autumn haze events of Beijing\",\"authors\":\"Huiying Xuan, Jun Liu, Yaqi Zhao, Qing Cao, Tianzeng Chen, Yonghong Wang, Zirui Liu, Xu Sun, Hao Li, Peng Zhang, Biwu Chu, Qingxin Ma, Hong He\",\"doi\":\"10.1038/s41612-024-00745-8\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Nitrous acid (HONO), a key precursor of hydroxyl radicals (OH), is one of the factors affecting atmospheric chemistry and air quality. Currently, the proposed sources of HONO are not able to fully explain observed HONO concentrations. In this study, a comprehensive field observation of HONO was conducted in the autumn of 2021 in urban Beijing. The box model using a default Master Chemical Mechanism (MCM) was unable to reproduce the observed HONO concentrations with a normalized mean bias (NMB) of −92.8%. The NMB improved to −46.1% after the inclusion of seven additional HONO formation pathways. Several factors like vehicle emission factor (1.23%) and nocturnal NO2 heterogeneous uptake coefficient on the ground surface (8.25 × 10−6) were calculated based on observational data. The enhancement factor for nocturnal NO2 heterogeneous conversion was established as a function of relative humidity (RH) and incorporated into the model, which compensated for the missing nocturnal HONO sources and well-reproduced the observed HONO concentrations, with an NMB of −5.1%. The major source of HONO at night was found to be the heterogeneous reaction of NO2 on the ground surface, contributing up to 85.6%. During the daytime, it was the homogeneous reaction of NO with OH, accounting for 41.8%. The daytime primary source of OH was mainly the photolysis of HONO, which constituted 73.6% and therefore promoted the formation of secondary pollutants and exacerbated haze events.\",\"PeriodicalId\":19438,\"journal\":{\"name\":\"npj Climate and Atmospheric Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":8.5000,\"publicationDate\":\"2024-08-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.nature.com/articles/s41612-024-00745-8.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"npj Climate and Atmospheric Science\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.nature.com/articles/s41612-024-00745-8\",\"RegionNum\":1,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"METEOROLOGY & ATMOSPHERIC SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"npj Climate and Atmospheric Science","FirstCategoryId":"89","ListUrlMain":"https://www.nature.com/articles/s41612-024-00745-8","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METEOROLOGY & ATMOSPHERIC SCIENCES","Score":null,"Total":0}
Relative humidity driven nocturnal HONO formation mechanism in autumn haze events of Beijing
Nitrous acid (HONO), a key precursor of hydroxyl radicals (OH), is one of the factors affecting atmospheric chemistry and air quality. Currently, the proposed sources of HONO are not able to fully explain observed HONO concentrations. In this study, a comprehensive field observation of HONO was conducted in the autumn of 2021 in urban Beijing. The box model using a default Master Chemical Mechanism (MCM) was unable to reproduce the observed HONO concentrations with a normalized mean bias (NMB) of −92.8%. The NMB improved to −46.1% after the inclusion of seven additional HONO formation pathways. Several factors like vehicle emission factor (1.23%) and nocturnal NO2 heterogeneous uptake coefficient on the ground surface (8.25 × 10−6) were calculated based on observational data. The enhancement factor for nocturnal NO2 heterogeneous conversion was established as a function of relative humidity (RH) and incorporated into the model, which compensated for the missing nocturnal HONO sources and well-reproduced the observed HONO concentrations, with an NMB of −5.1%. The major source of HONO at night was found to be the heterogeneous reaction of NO2 on the ground surface, contributing up to 85.6%. During the daytime, it was the homogeneous reaction of NO with OH, accounting for 41.8%. The daytime primary source of OH was mainly the photolysis of HONO, which constituted 73.6% and therefore promoted the formation of secondary pollutants and exacerbated haze events.
期刊介绍:
npj Climate and Atmospheric Science is an open-access journal encompassing the relevant physical, chemical, and biological aspects of atmospheric and climate science. The journal places particular emphasis on regional studies that unveil new insights into specific localities, including examinations of local atmospheric composition, such as aerosols.
The range of topics covered by the journal includes climate dynamics, climate variability, weather and climate prediction, climate change, ocean dynamics, weather extremes, air pollution, atmospheric chemistry (including aerosols), the hydrological cycle, and atmosphere–ocean and atmosphere–land interactions. The journal welcomes studies employing a diverse array of methods, including numerical and statistical modeling, the development and application of in situ observational techniques, remote sensing, and the development or evaluation of new reanalyses.