- Study on the characteristics of atmospheric CO2 and CH4 concentration variations at Ganzhou Station in Jiangxi
- Abstract：Based on the high-precision online observation data of atmospheric CO2 and CH4 mixing ratios at Ganzhou Station in Jiangxi from December 2018 to November 2019, the variations of CO2 and CH4 mixing ratios and the impact of regional atmospheric transportation, and the distribution of potential emission source areas were discussed. Results showed that during the study period, the average mixing ratios of CO2 and CH4 at Ganzhou Station were 433.1×10-6 and 2142.5×10-9, respectively. The daily variations of CO2 and CH4 mixing ratios at Ganzhou Station both exhibited minimum values during daytime and maximum values in morning and evening. The largest and smallest daily amplitude of CO2 mixing ratio of 29.7×10-6 and 6.9×10-6 were observed in summer and winter, respectively. The largest and smallest daily amplitude of CH4 mixing ratio were observed as 145.1×10-9 in autumn and 41.4×10-9 in winter, respectively. The background CO2 mixing ratio showed a typical seasonal pattern with a rapid decline from April to August, and a gradual increase from August to November, with the maximum value in January and the minimum value in August, and the seasonal amplitude was 26.2×10-6. The seasonal variation of CH4 showed a gradual decrease from January to July, and a gradual increase from July to September. The maximum value appeared in January and the minimum value appeared in July with the seasonal amplitude of 79.5×10-9, which was typical representative of seasonal variations in CO2 and CH4 in the uniformly mixed atmosphere in Ganzhou, Jiangxi. The comparison results showed that the background mixing ratios of CO2 and CH4 at the Ganzhou Station were lower than those at the Nanchang Station in each season. The potential sources of CO2 and CH4 in Ganzhou mainly distributed in northern Jiangxi, eastern Hubei, southern Anhui, and the Pearl River Delta.