拉萨上空对流层NO_(2)柱浓度光谱反演及其变化特征研究  

Spectral Inversion and Variation Characteristics of Tropospheric NO_(2) Column Density in Lhasa,Tibet

作　　者：蒲桂娟 程巳阳[3] 李松奎[4] 吕金光[2] 陈华 马建中[3] PU Gui-juan;CHENG Si-yang;LI Song-kui;L Jin-guang;CHEN Hua;MA Jian-zhong(Tibet Institute of Plateau Atmospheric and Environmental Sciences,Lhasa 850000,China;State Key Laboratory of Applied Optics,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;State Key Laboratory of Severe Weather&Institute of Tibetan Plateau Meteorology,Chinese Academy of Meteorological Sciences,Beijing 100081,China;Meteorological Observation Centre,China Meteorological Administration,Beijing 100081,China;Tibet Autonomous Region Atmospheric Detection Technology and Equipment Support Center,Lhasa 850000,China)

机构地区：[1]西藏高原大气环境科学研究所,西藏拉萨850000 [2]中国科学院长春光学精密机械与物理研究所,应用光学国家重点实验室,吉林长春130033 [3]中国气象科学研究院,灾害天气国家重点实验室和青藏高原气象研究所,北京100081 [4]中国气象局气象探测中心,北京100081 [5]西藏自治区大气探测技术与装备中心,西藏拉萨850000

出　　处：《光谱学与光谱分析》2023年第6期1725-1730,共6页Spectroscopy and Spectral Analysis

基　　金：应用光学国家重点实验室开放基金课题(SKLAO2021001A02);中国气象局软科学研究项目(2021ZZXM21);中国气象局创新发展专项(CXFZ2022P020)资助。

摘　　要：基于多轴差分吸收光谱技术(MAX-DOAS)开展拉萨上空太阳散射光谱观测和对流层NO_(2)柱浓度反演研究,探究西藏和平解放70周年大庆活动期间拉萨上空NO_(2)对流层垂直柱浓度变化特征。研究结果表明:观测实验期间(2021年8月9日至2021年8月31日)白天NO_(2)对流层垂直柱浓度的平均值为4.46×10^(15)molec·cm^(-2),明显高于西藏和平解放70周年大庆活动日当天NO_(2)浓度水平(2.85×10^(15)molec·cm^(-2));而且NO_(2)对流层垂直柱浓度日均值的逐日变化与地面在线观测数据具有良好相关性,相关系数为0.58。观测实验期间拉萨市主导风向为西风,东西方向是大气NO_(2)污染物的传输通道,这与拉萨城区河谷地形相一致。观测实验期间NO_(2)对流层垂直柱浓度小时均值的平均日变化呈现“U”型分布,早晚出现高值,低值浓度出现在16:00时左右,但西藏和平解放70周年大庆活动日当天NO_(2)对流层垂直柱浓度的日变化除表现为早晚峰值外,还在正午12:00时出现峰值,这与活动结束后道路管控措施解除以及活动保障车辆行驶排放有关。本研究证实了地基MAX-DOAS遥感观测技术在高原城市拉萨具有很好地适用性,同时也发现拉萨大气NO_(2)浓度水平变化主要受城市交通排放影响,西藏和平解放70周年大庆活动当日拉萨对流层大气NO_(2)浓度低。The observation of solar scattering spectra was performed at Lhasa by Multi Axis Differential Optical Absorption Spectroscopy(MAX-DOAS),which was used to retrieve the tropospheric vertical column densities(VCD trop)of nitrogen dioxide(NO_(2))in order to investigate the variation characteristics of NO_(2) during the celebration period of the 70th anniversary of the peaceful liberation of Tibet.During the observation period(9 August 2021 to 31 August 2021),the averaged NO_(2) VCD trop in the daytime was 4.46×1015 molec·cm^(-2),significantly higher than that on the celebration day of the 70th anniversary of the peaceful liberation of Tibet(2.85×1015 molec·cm^(-2)).In addition,the daily averages of NO_(2) VCD trop presented a good correlation with the results measured by the online surface observation,with a correlation coefficient of 0.58.During the observation experiment,the prevailing wind direction in Lhasa was westerly,and the east-west direction was the transport path of atmospheric NO_(2),which was consistent with the river valley topography of Lhasa city.The average diurnal variation of the hourly means of NO_(2) VCD trop showed a“U”pattern,with higher values appearing in the morning and evening,and lower values occurring around 16:00.However,on the celebration day of the 70th anniversary of the peaceful liberation of Tibet,the diurnal variation of NO_(2) VCD trop not only presented the peak values in the morning and evening but also at noon,which probably was related to the removal of road control measures after the activity and the emission of support vehicle.In conclusion,this study confirmed the good applicability of ground-based MAX-DOAS remote sensing in the typical city of Lhasa over the Tibetan Plateau.Meanwhile,it was also found that the level and variation of NO_(2) VCD trop in Lhasa were mainly affected by urban traffic emissions.The atmospheric NO_(2) concentration in Lhasa was lower on the celebration day of the 70th anniversary of the peaceful liberation of Tibet.

关 键 词：多轴差分吸收光谱技术 二氧化氮 对流层柱浓度 拉萨 

分 类 号：O433.4[机械工程—光学工程]