南极考察航线大气微、痕量气体观测:数据质量评估/控制与分析  

Observations of atmospheric trace gases along the R/V Beijing cruise track between China and Antarctica:Data QA/QC and preliminary results

作　　者：邹炫宇 赵守栋 汤洁[1] 郑向东[1] 张东启[1] 卞林根[1] ZOU Xuanyu;ZHAO Shoudong;TANG Jie;ZHENG Xiangdong;ZHANG Dongqi;BIAN Lingen(Chinese Academy of Meteorological Sciences,Beijing 100081,China)

机构地区：[1]中国气象科学研究院,北京100081

出　　处：《气象学报》2023年第5期838-852,共15页Acta Meteorologica Sinica

基　　金：国家自然科学基金项目(41775031);中国气象科学研究院科技发展基金项目(2023kJ014)。

摘　　要：在远洋航船上开展大气成分观测易受到来自航船燃油发动机排放污染。基于2020年1-4月“北京”号考察船南极考察航线微量(CO_(2))和痕量(CO、O_(3)、CH_(4)和N_(2)O)气体浓度(体积混合比)观测分钟级数据,提出根据CO、CO_(2)测量值开展数据质量评估与控制(QA/QC),并给出了南极考察航线上大气微、痕量气体分布特征。结果表明,以CO或CO_(2)单独示踪均能标识出数据的部分局地污染时段,但CO/CO_(2)比值对确定高污染时段的CO或CO_(2)本底浓度更有效,CO和CO_(2)同步示踪(即CO+CO_(2))是标识局地污染时段的最优方法,可使南大洋和南极地区的CO、CO_(2)浓度测量值分别降低(5-11)×10^(-9)(10%-18%)和(3-7)×10^(-9)(1%-2%),O3上升(3-5)×10^(-9)(20%-25%),测量值更具有全球本底特征的代表性。航船测量数据与同纬度陆地站点观测值接近,南大洋和南极地区CO、CO_(2)、CH_(4)和N_(2)O浓度差分别在2×10^(-9)、0.7×10^(-6)、1.4×10^(-9)和0.5×10^(-9)以内。航线的微、痕量气体测量值均呈北(南)半球高(低)、南大洋以南及南极地区浓度稳定的基本特征;O3在不同纬度分布特点清晰,热带辐合带(ITCZ)的极低浓度(<5×10^(-9))和春季中国东海地区出现的中尺度污染现象均很明显。Atmospheric chemistry observations aboard ships are vulnerable to pollution from ship fuel engine exhaust.This local pollution leads to an increase in CO and CO_(2)and a decrease in O_(3).Concentrations(presented as volume mixing ratio)of CO,CO_(2),O_(3),CH_(4)and N_(2)O in the marine-atmosphere boundary layer were measured along the R/V Beijing cruise track between Bohai bay of China and the Ross sea in Antarctica from January to April 2020.Based on the successive observations of 1-minute resolution,the impact of local pollution emission on the measured values of each trace gas is respectively implied by the persistence of variations in CO,CO_(2),and combinations of CO and CO_(2)and CO/CO_(2)for the study of data quality assessment quality controls(QA/QC).The results show that CO,CO_(2)and O_(3)(CH_(4)and N_(2)O)data are significantly(slightly)contaminated by local pollution.A method of trace concentration difference threshold between any immediate adjacent 1-minute is proposed,which can effectively remove the outliers of CH_(4)and N_(2)O from their time series datasets.The pollution period implied by CO or CO_(2)can be partially but not completely used to identify the contaminations in the dataset.The ratio of CO/CO_(2)implication can effectively determine the global baseline concentration of CO or CO_(2)in highly polluted region but at a high cost of discarding many data samples.The combination of CO_(2)and CO(CO_(2)+CO)is the best method to imply the pollution signals in the CO_(2),CO and O_(3)datasets,and this method decreases the measured values of CO and CO_(2)concentrations in the southern hemisphere and the pristine region by(5—11)×10^(−9)(10%—18%)and(3—7)×10^(−6)(1%—2%)respectively,while O_(3)increases by(3—5)×10^(−9)(20%—25%).The final version concentration data of each trace gas are reasonably comparable with those measured at continental sites and the concentration differences of CO,CO_(2),CH_(4)and N_(2)O in the southern ocean and Antarctica are respectively within 2×10^(−9),

关 键 词：局地污染 CO和CO_(2)示踪 数据质量评估与控制(QA/AC) 南极考察船航线 微、痕量气体 

分 类 号：P402[天文地球—大气物理学与大气环境]