Deriving Temporal and Vertical Distributions of Methane in Xianghe Using Ground-based Fourier Transform Infrared and Gas-analyzer Measurements
Earth and related Environmental sciences
Fourier transform infrared spectrometer (FTIR)
MetadataShow full item record
Methane (CH4) is one of the most important greenhouse gases in the atmosphere, making it worthwhile to study its temporal and vertical distributions in source areas, e.g., North China. For this purpose, a ground-based high-resolution Fourier transform infrared spectrometer (FTIR), the Bruker IFS 125HR, along with an in-situ instrument, the Picarro G2301, were deployed in Xianghe County (39.8°N,117.0°E), Hebei Province, China. Data have been recorded since June 2018. For the FTIR measurements, we used two observation modes to retrieve the mole fraction of CH4: the Total Carbon Column Observing Network (TCCON) method (retrieval algorithm: GGG2014), and the Network for the Detection of Atmospheric Composition Change (NDACC) method (retrieval algorithm: SFIT4). Combining FTIR with in-situ measurements, we found the temporal and vertical distributions of atmospheric CH4 within three vertical layers (near the ground, in the troposphere, and in the stratosphere), and throughout the whole atmosphere. Regarding the diurnal variation of CH4 near the ground, the concentration at night was higher than during the daytime. Regarding the seasonal variation, CH4 was low in spring and high in summer, for all three vertical layers. In addition, there was a peak of CH4 in winter near the ground, both in the troposphere and the whole atmosphere. We found that variation of CH4 in the tropospheric column was close to that of the in-situ measurements near the ground. Furthermore, the variations of CH4 in the stratospheric column could be influenced by vertical motions, since it was higher in summer and lower in winter.
CitationJi, D.; Zhou, M.; Wang, P.; Yang, Y.; Wang, T.; Sun, X.; Hermans, C.; Yao, B.; Wang, G. (2020). Deriving Temporal and Vertical Distributions of Methane in Xianghe Using Ground-based Fourier Transform Infrared and Gas-analyzer Measurements. , Advances in Atmospheric Sciences, Vol. 37, Issue 6, 597-607, DOI: 10.1007/s00376-020-9233-4.