Study of atmospheric CO2 and CH4 at Longfengshan WMO/GAW regional station: The variations, trends, influence of local sources/sinks, and transport
Study of atmospheric CO2 and CH4 at Longfengshan WMO/GAW regional station: The variations, trends, influence of local sources/sinks, and transport
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DOI：
10.1007/s11430-016-9066-3
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发表时间：
2017-07
期刊：
影响因子：
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通讯作者：
S. Fang;P. Tans;B. Yao;T. Luan;Yan-ling Wu;Dajiang Yu
中科院分区：
文献类型：
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作者：
S. Fang;P. Tans;B. Yao;T. Luan;Yan-ling Wu;Dajiang Yu
自2009年以来，在中国龙凤山气象站（LFS）对大气CO2和CH 4进行了连续观测。利用2009 - 2013年的观测资料，分析了大气中水汽的摩尔分数变化、远距离输送的影响、局地源/汇的影响以及天气尺度的变化特征。CO2和CH 4的摩尔分数在过去五年中均呈现出增长趋势，CO2的增长率为3.1±0.02 ppm/年，CH 4的增长率为8±0.04 ppb/年（标准误差，1-σ）。夏季区域CO2浓度明显低于海洋边界层参考值，最低值出现在7月，为13.6± 0.7ppm;而CH 4浓度则高于海洋边界层参考值，最高值为139± 6ppb。夏季9 ~ 17时（当地时间，LT），10 m a.g.l.在80 m处的平均浓度差为1.1±0.2 ppm，表明夏季采用的烧瓶采样方法可能低估了背景浓度。在冬季，人为排放占主导地位的区域CO2和CH 4的摩尔分数。后向轨迹的聚类分析表明，大气CO2和CH 4在LFS全年受西南地区（长春和吉林）人为排放的影响。天气尺度的变化表明，东北平原是冬季大气CO2和CH 4的重要来源。
Atmospheric CO2and CH4have been continuously measured since 2009 at Longfengshan WMO/GAW station (LFS) in China. Variations of the mole fractions, influence of long-distance transport, effects of local sources/sinks and the characteristics of synoptic scale variations have been studied based on the records from 2009 to 2013. Both the CO2and CH4mole fractions display increasing trends in the last five years, with growth rates of 3.1±0.02 ppm yr‒1for CO2and 8±0.04 ppb yr‒1(standard error, 1-σ) for CH4. In summer, the regional CO2mole fractions are apparently lower than the Marine Boundary Layer reference, with the lowest value of‒13.6±0.7 ppm in July, while the CH4values are higher than the MBL reference, with the maximum of 139±6 ppb. From 9 to 17 (Local time, LT) in summer, the atmospheric CO2mole fractions at 10 m a.g.l. are always lower than at 80 m, with a mean difference of‒1.1±0.2 ppm, indicating that the flask sampling approach deployed may underestimate the background mole fractions in summer. In winter, anthropogenic emissions dominate the regional CO2and CH4mole fractions. Cluster analysis of backward trajectories shows that atmospheric CO2and CH4at LFS are influenced by anthropogenic emissions from the southwest (Changchun and Jilin city) all year. The synoptic scale variations indicate that the northeastern China plain acts as an important source of atmospheric CO2and CH4in winter.