title: [Atmospheric CH4 concentrations and the correlation between CH4 and CO concentrations].
abstract: Methane (CH4) is an important greenhouse gas and a key molecule in tropospheric photochemistry, some more potent than CO2. The remote-sensing experiments of CH4 were carried out in the fall of 2 000 in Beijng. The 6-day records of the atmospheric CH4 concentrations were examined by means of a time-series analysis using a fast Fourier transform with a low-pass filter to elucidate the seasonal cycles and the long-term trends. The variation in the long-time trends of the CH4 concentrations in Beijing may be ascribed to the emission changes in the CH4 sources due to the human activities such as waste dumping and landfills and the emission from motor vehicles. The correlation between the CH4 and CO concentrations was analyzed.
authors.affiliation: Chinese Academy of Sciences, Anhui Institute of Optics and Fine Machanics, Hefei 230031, China. xlwei@aiofm.ac.cn
authors.forename: Xiu-Li
authors.initials: XL
authors.lastname: Wei
authors.forename: Yi-Huai
authors.initials: YH
authors.lastname: Lu
authors.forename: Min-Guang
authors.initials: MG
authors.lastname: Gao
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Liu
authors.forename: Wen-Qing
authors.initials: WQ
authors.lastname: Liu
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.forename: Tian-Shu
authors.initials: TS
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Chen