北京市和厦门市大气CO_2浓度及δ^(13)C值变化特征  

Variational characteristics of CO_2 concentrations and δ^(13)C values at the urban sites in Beijing and Xiamen, China

作　　者：冯雪 王森[1,2] 牛振川[3,4] FENG Xue;WANG Sen;NIU Zhenchuan(College of Urban and Environmental Sciences,Northwest University,Xi’an 710127,China;Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity,Northwest University,Xi’an 710127,China;State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710061,China;Xi’an Accelerator Mass Spectrometry Center,Xi’an 710061,China)

机构地区：[1]西北大学城市与环境学院,西安710127 [2]西北大学陕西省地表系统与环境承载力重点实验室,西安710127 [3]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710061 [4]西安加速器质谱中心,西安710061

出　　处：《地球环境学报》2018年第4期316-322,共7页Journal of Earth Environment

基　　金：国家自然科学基金项目(41573136;41773141);中国科学院"西部之光"(XAB2014A02);中国科学院青年创新促进会(2016360)~~

摘　　要：本文对北京市和厦门市大气CO_2及δ^(13)C进行观测,研究内陆城市和沿海城市CO_2浓度及δ^(13)C的季节和昼夜变化规律及影响因素,以期为政府制定碳减排政策提供科学依据。北京市和厦门市CO_2浓度均呈现秋冬季高于春夏季,而δ^(13)C秋冬季低于春夏季,季节差异原因可能是秋冬大气边界层降低,化石燃料消耗增加,贫13C的CO_2气体大量排放。观测期间,两个城市日变化模式均表现为CO_2夜间高于白天,δ^(13)C夜间低于白天;且在早晚交通高峰时段,两地CO_2浓度均有不同程度升高,而δ^(13)C有不同程度降低。冬季,北京市由于受西、北部高山阻挡,在东南风条件下使得其夜间大气CO_2浓度显著增高,δ^(13)C值则显著降低。根据两地新增CO_2的δ^(13)C值(δs)推测,北京市受到煤炭燃烧贡献较大,厦门市季节差异较大,推测受植物排放CO_2速率及气象条件等共同影响。Background,aim,and scope To mitigate the global warming,more and more attention of the environmental scientists are focused on atmospheric CO2 increase.Urban areas are hotspots of anthropogenic CO2 emission sources.It is necessary to monitor the feature of CO2 variations in urban areas.The data of CO2 concentration and the stable carbon isotope ratio(δ^13C)are important for CO2 reduction in urban areas.Therefore,the variation in CO2 andδ13C in urban areas are observed in this paper.The study presented the data of atmospheric CO2 concentrations andδ^13C values at the urban sites in the inland city of Beijing and in the coastal city of Xiamen,to study the seasonal and diurnal variation in CO2 concentration andδ^13C during 2014,and their key factors.Materials and methods In this study,we measured the CO2 concentration and itsδ13C at the urban sampling sites in Beijing and Xiamen,respectively.Beijing is a typical inland city,which is located in the northwest of the North China Plain,surrounded by West Mountain and Jundu Mountain.It is the center of the Beijing-Tianjin-Hebei metropolitan region,with a population of more than 20 million.Xiamen is one of the cities in southeast coastal areas,facing the Taiwan Strait,with a resident population of more than 4 million.There is no direct pollution sources around the sampling sites in Beijing and Xiamen.We used aluminum foil sampling bags to collect the air samples and collected 144 urban air samples in this study.The CO2 concentrations andδ^13C of samples were measured by the Picarro G2131-ⅠCO2 Isotopic Analyzer(Picarro Inc.)with cavity ring down spectroscopy(CRDS).This analyzer has a characteristic of highly linearity and accuracy in CO2 andδ^13C measurements(error<0.1‰).The CO2 andδ^13C value for each sample was measured for 6 minutes,and the average of the data from the last 4 min was used,to avoid equipment instability created by dead volumes when switching a new sample.Results The results showed that the CO2 concentrations in Beijing and Xiamen were high in

关 键 词：大气CO2浓度 Δ^13C 季节变化 昼夜变化 Keeling曲线 

分 类 号：X51[环境科学与工程—环境工程]