Occurrence and Discrepancy of Surface and Column Mole Fractions of CO2 and CH4 at a Desert Site in Dunhuang, Western China

Atmosphere

Lingbing Bu¹  Jiqiao Liu²  Zheng Lyu³  Chong Wei³ 

[1]Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Key Laboratory of Meteorological Disasters of Ministry of Education, Nanjing University of Information Science and Technology (NUIST), Nanjing 210044, China

[2]Key Laboratory of Space Laser Communication and Detection Technology, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China

[3]Shanghai Carbon Data Research Center, CAS Key Laboratory of Low-Carbon Conversion Science and Engineering, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai 201210, China

关键词: greenhouse gases;    column mole fractions;    satellite;    Gobi Desert;    temporal variation;    meteorological conditions;   

DOI  :  10.3390/atmos13040571

来源: DOAJ

【 摘 要 】

Carbon dioxide (CO₂) and methane (CH₄) are the two major radiative forcing factors of greenhouse gases. In this study, surface and column mole fractions of CO₂ and CH₄ were first measured at a desert site in Dunhuang, west China. The average column mole fractions of CO₂ (XCO₂) and CH₄ (XCH₄) were 413.00 ± 1.09 ppm and 1876 ± 6 ppb, respectively, which were 0.90 ppm and 72 ppb lower than their surface values. Diurnal XCO₂ showed a sinusoidal mode, while XCH₄ appeared as a unimodal distribution. Ground observed XCO₂ and XCH₄ were compared with international satellites, such as GOSAT, GOSAT-2, OCO-2, OCO-3, and Sentinel-5P. The differences between satellites and EM27/SUN observations were 0.26% for XCO₂ and −0.38% for XCH₄, suggesting a good consistency between different satellites and ground observations in desert regions in China. Hourly XCO₂ was close to surface CO₂ mole fractions, but XCH₄ appeared to have a large gap with CH₄, probably because of the additional chemical removals of CH₄ in the upper atmosphere. It is necessary to carry out a long-term observation of column mole fractions of greenhouse gases in the future to obtain their temporal distributions as well as the differences between satellites and ground observations.

【 授权许可】

Unknown