苏南地区CO2本底浓度及源汇特征  

A study on background concentration and source-sink characteristics of CO2 in south of Jiangsu

作　　者：韦芬芬[1] 林惠娟[1] 曹舒娅 沈沛丰[1] 惠品宏 WEI Fen-fen;LIN Hui-juan;CAO Shu-ya;SHEN Pei-feng;HUI Pin-hong(Suzhou Meteorological Bureau,Suzhou 215131,China;Jiangsu Climate Center,Nanjing 210009,China)

机构地区：[1]苏州市气象局,江苏苏州215131 [2]江苏省气候中心,江苏南京210009

出　　处：《中国环境科学》2020年第3期975-982,共8页China Environmental Science

基　　金：江苏省气象局科研项目(JSYBY201915);苏州市科技计划项目(SS2019033)。

摘　　要：基于2015-2018年苏州张家港站CO2在线观测数据,采用时序检查、选取稳定性数据、异常值剔除等质量控制方法获得可靠数据,并通过平均移动过滤(MAF)本底筛分法获得本底数据,讨论苏南地区CO2变化特征.结果发现:CO2本底浓度日变化为单峰结构,谷值和峰值分别出现在下午15:00和凌晨5:00前后;季节变化为双峰结构,峰值分别出现在12月和4月;日、季节变化的分布特征均与陆地生态系统气象条件和人类活动有关.此外,2015-2018年CO2浓度呈逐年上升趋势,抬升浓度占比逐年增加,吸收浓度占比波动较小,表明人类活动对CO2浓度的影响正在逐年增加;而陆地生态系统对CO2吸收汇的作用则相对稳定.源汇分析显示,CO2抬升浓度随季节小幅波动;吸收浓度则夏半年较低,冬半年较高;抬升浓度日变化为单峰结构,谷值和峰值分别出现在15:00和8:00前后,早晨正值上班高峰,机动车排放可能为早晨峰值的主要因素;吸收浓度日间低夜间高,这主要与植物光合作用及对流输送有关.分析CO2浓度与风的关系发现,所有季节静风情况下,CO2浓度偏高均最为明显,大部分方向CO2浓度高低与风速大小有明显的负相关,其中S-WNW方向偏高最为明显,这可能是因为SW-NW方向主要为内陆城市群,且测站周边建筑区主要位于W-N方向,弱风有利于本地排放累积的结果.此外,WNW方向风速较大时浓度仍偏高明显,可能与测站W-N方向为建筑区及内陆城市群有关;而测站偏东方向主要为农田和林区,受人类活动影响较小,且海上气流较为洁净,故偏东风较弱时浓度也不高;说明了CO2浓度除了与风速大小有关外,与周边下垫面类型及较远距离环境特征(城市群或海洋)也有一定的关系.By quality control methods(i.e.,time series inspection,selection of stability data and eliminating the abnormal values),high-quality CO2 datasets of Zhangjiagang Station in Suzhou from 2015 to 2018 were obtained to study the background concentration and source-sink characteristics of CO2 in Suzhou.By Moving Average Filtering(MAF)method,CO2 datasets have been separated as background and non-background data.The background data showed that the diurnal variation of CO2 background concentration showed a single peak structure,and the peak and valley value was around 5:00 a.m.and 15:00 p.m,respectively.The seasonal variation showed a double peak structure,with the peaks in December and April.Both of the distribution of daily and seasonal variation of CO2 were related to terrestrial ecosystems,meteorological conditions and human activities.From 2015 to 2018,the CO2 concentration has increased.Particularly,the proportion of rising concentration has significantly increased,which may due to the human activities.On the contrast,the variation of the absorption concentration was stable,which inferred that the role of terrestrial ecosystem on CO2 concentration was relatively stable.The source-sink analysis showed that,seasonally,the CO2 uplifting concentration fluctuated slightly,while the absorption concentration showed remarkable seasonally variations.The diurnal variation of the rising concentration was a single-peak structure,with the peak value around 8:00 a.m.,which may be traced to the high motor vehicle emissions in the morning.The absorption concentration was low in the daytime and high in the nighttime,which may be related to the plant photosynthesis and convective transport.We further analyzed the relationship between the CO2 concentration and the wind field.The high CO2 concentration has prevailed under the condition of calm wind in all seasons.Generally,in most wind directions,the concentration of CO2 was negatively correlated with the wind speed.Particularly,the high CO2 concentration was mostly accompanied at sou

关 键 词：温室气体 城市背景 源汇特征 风 

分 类 号：X511[环境科学与工程—环境工程]