山西省城市大气CO2本底筛分对比及特征分析

基于典型城市站太原站2018年3月—2019年2月的大气CO₂在线观测资料，利用筛分法(Meteorological filtering method, MET)和黑碳示踪法(Black Carbon tracer, BC)进行本底/非本底的筛分，得到了本底浓度的变化特征。结果表明，太原大气CO₂浓度季均值冬季最高，夏季最低；不同季节呈“单峰型”日变化特征，日振幅均在26.0×10^-6以上；4个季节CO₂浓度与地面风速存在显著负相关关系；CO₂浓度抬升区域主要受当地工业布局的影响，最大抬升幅度在秋季达17.4×10^-6;使用气象筛分法(MET)得到年均本底浓度为(431.4±19.9)×10^-6,人为排放等对其影响为23.5×10^-6,年振幅比同纬度其它本底站大，为34.5×10^-6;黑碳示踪法(BC)得到冬季季均本底浓度为(445.0±22.9)×10^-6,比MET筛...

Comparison and characteristic analysis of background filtering methods for urban atmospheric CO2 in Shanxi

This paper analyzed the on-line observation data of atmospheric CO₂ at Taiyuan station, where a typical urban station, from March 2018 to February 2019. Meteorological filtering method (MET) method and Black Carbon tracer method (BC) method were used to obtain background concentration and non-background concentration. The variation characteristics of background concentration were studied. Results show that the seasonal average value of atmospheric CO₂ concentration in Taiyuan is the highest in winter and the lowest in summer; the four seasons diurnal variations have "single peak", with daily amplitude above 26.0×10^-6; the four seasons have significant negative correlation between CO₂ concentration and surface wind speed; the rising area of CO₂ concentration is mainly affected by the local industrial layout, and the maximum uplift amplitude can reach 17.4×10^-6 in autumn. The average annual background concentration filtered by MET is (431.4 ±19.9)×10^-6, the influence of anthropogenic emissions is 23.5×10^-6, and the annual amplitude is 34.5×10^-6, which is larger than other background stations at the same latitude. The average background concentration filtered by BC is (445.0 ±22.9)×10^-6, which is 0.8×10^-6 higher than that filtered by MET, the variation trend of CO₂ concentration obtained by the two filtering methods is the same.