光谱遥感揭示北京市在重大事件和节假日期间的NO_(2)垂直廓线变化差异  

Spectral Remote Sensing of NO_(2) Vertical Profile Variation Difference in Beijing During Major Events and Holidays

作　　者：陈健 邢成志 林继楠 刘诚 Chen Jian;Xing Chengzhi;Lin Jinan;Liu Cheng(Department of Precision Machinery and Precision Instrumentation,University of Science and Technology of China,Hefei 230026,Anhui,China;Key Laboratory of Environmental Optics&Technology,Chinese Academy of Sciences,Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,Anhui,China)

机构地区：[1]中国科学技术大学精密机械与精密仪器系,安徽合肥230026 [2]中国科学院合肥物质科学研究院安徽光学精密机械研究所中国科学院环境光学与技术重点实验室,安徽合肥230031

出　　处：《光学学报》2024年第24期60-71,共12页Acta Optica Sinica

基　　金：国家自然科学基金(U21A2027);国家重点研发计划(2019YFC0214702);安徽省自然科学基金(2108085QD180)。

摘　　要：基于搭设于中国气象科学研究院的多轴差分吸收光谱(MAXDOAS)站点,获得北京市2020年6月1日至2022年5月31日的二氧化氮(NO_(2))垂直廓线,底层体积分数与中国环境监测总站(CNEMC)官园站点的NO_(2)质量浓度的相关性较高(R=0.7723)。研究结果表明,北京市近地面NO_(2)最高体积分数出现在1月(17.40×10^(-9)),最低体积分数出现在4月(5.51×10^(-9))。季节特征表现为冬季(15.71×10^(-9))>秋季(15.39×10^(-9))>春季(8.52×10^(-9))>夏季(8.06×10^(-9))。不同季节NO_(2)体积分数廓线均呈e指数型,春夏季NO_(2)体积分数平均日变化呈现单峰模式,峰值出现在10:00之前,秋冬季NO_(2)体积分数平均日变化呈现双峰模式,峰值分别出现在10:00之前和15:00以后。从体积分数变化的角度并未发现北京市NO_(2)存在明显的周末效应,然而在日变化模式上却展现出显著的周末效应,主要表现为周六上午的NO_(2)峰值(16.16×10^(-9))相较于工作日和周日更大,且在时间上相较于工作日和周日存在延后,而周日下午的NO_(2)峰值显著高于工作日和周六,这可能与北京市周六集中跨城出行且在周日集中返回有关。此外,重大事件期间NO_(2)降低幅度明显大于节假日期间。重大事件期间和节假日期间底层NO_(2)平均体积分数相较于整个观测期间分别下降了29.0%和18.5%。本研究通过长期MAXDOAS观测揭示了北京市NO_(2)的垂直分布季节特征和日变化模式,发现了独特的周末效应,评估了政策性减排和节假日对NO_(2)的影响,对深入理解和有效控制NO_(2)污染具有重要意义。Objective Nitrogen dioxide(NO_(2))not only directly affects air quality and participates in secondary chemical reactions but also influences human health.It primarily originates from industrial and vehicular emissions,as well as regional transport at higher altitudes.Therefore,surface in situ measurements alone cannot fully comprehend the highaltitude transport,vertical evolution,and atmospheric chemical processes of NO_(2).In this study,we aim to investigate the vertical distribution characteristics and temporal variations of NO_(2) in Beijing,given its status as a primary atmospheric pollutant originating from industrial activities and vehicular emissions.With Beijing’s dense population and high vehicle density,vehicular emissions constitute a major source of NO_(2).Despite improvements in air quality due to environmental policies,regional transport,especially along the southwest‒northeast corridor,remains a significant contributor to NO_(2) levels in Beijing.Traditional monitoring methods have limitations in capturing NO_(2) transport dynamics,necessitating advanced techniques such as multiaxis differential optical absorption spectroscopy(MAXDOAS).This research,based on two years of MAXDOAS observations,is designed to understand NO_(2)’s vertical distribution and its response to policy interventions and holiday effects.By providing detailed insights into NO_(2) behavior under various conditions,we support effective air quality management and policy formulation in Beijing.Methods Our study examines the spatiotemporal distribution of NO_(2) in Beijing using a MAXDOAS observation station located at the Chinese Academy of Meteorological Sciences from June 1,2020,to May 31,2022.Positioned at an elevation of 130 m,the instrument is situated 40 m above ground level with a viewing azimuth of 130°.The station is strategically placed near major NO_(2) emission sources from busy traffic areas within a 5 km radius,despite the absence of industrial emissions.The MAXDOAS instrument comprises modules for collecting su

关 键 词：光谱学 二氧化氮 垂直分布 季节变化 周末效应 冬奥会 

分 类 号：O433.1[机械工程—光学工程]