江西赣州站大气CO2和CH4浓度变化特征研究

通过分析2018年12月—2019年11月江西赣州站大气CO₂和CH₄浓度高精度在线观测资料，对其CO₂和CH₄浓度变化特征进行了研究，分析了区域大气输送的影响以及潜在排放源区分布特征.结果表明：研究期内赣州站CO₂和CH₄的平均浓度分别为433.1×10^-6和2142.5×10^-9.赣州站CO₂和CH₄浓度日变化均表现为日间低、早晚高，CO₂浓度日振幅在夏季最大，为29.7×10^-6，冬季最小，为6.9×10^-6.CH₄浓度日振幅在秋季最大，为145.1×10^-9，冬季最小，为41.4×10^-9.CO₂本底浓度季节变化表现为4—8月迅速下降，8—11月逐渐上升，最大值出现在1月，最小值出现在8月，季节振幅为26.2×10^-6.CH₄本底浓度季节变化表现为1—7月逐渐下降，7—9月逐渐上升，最大值出现在1月，最小值出现在7月，季节振幅为79.5×10^-9，基本可代表江西赣州地区混合均匀大气的CO₂和CH₄季节变化状况.与南昌站对比分析表明，赣州站各季节CO₂和CH₄本底浓度均低于南昌站.赣州地区CO₂和CH₄潜在源区主要分布在江西北部、湖北东部、安徽南部和珠江三角洲地区.

Study on the characteristics of atmospheric CO2 and CH4 concentration variations at Ganzhou Station in Jiangxi

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.