“Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the capti...“Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the caption of Fig.8 on Page 604 should be“Diurnal variation of CH4 at the surface from spring to winter.The time units are in UTC.The error bar is 1σfor all the observed hourly mean data within that season at that local time.”展开更多
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-r...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 125 HR,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 June2018.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.展开更多
文摘“Diurnal variation of CH4 at the surface from spring to winter.The time units are in local time(+8 h UTC).The error bar is 1σfor all the observed hourly mean data within that season at that local time.”in the caption of Fig.8 on Page 604 should be“Diurnal variation of CH4 at the surface from spring to winter.The time units are in UTC.The error bar is 1σfor all the observed hourly mean data within that season at that local time.”
基金funded by the National Key R&D Program of China(Grant Nos.2017YFB0504000 and 2017YFC1501701)the National Natural Science Foundation of China(Grant No.41975035)。
文摘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 125 HR,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 June2018.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.
