摘要
近几年大气中CFC的浓度在人类活动的影响下发生了迅速变化 ,考虑到CFC浓度变化对平流层臭氧和全球变暖的影响 ,采用两步深冷冻浓缩自动进样系统 ,配以气相色谱 /质谱联机对北京大气中的CFC 11进行了连续观测 .结果表明 ,1999～2 0 0 3年CFC 11的浓度季节变化均呈单峰形态 ,峰值出现在 7～ 8月 ,月平均浓度最高值为 114 9 5± 5 31 9× 10 -12 (体积分数 ) ;谷值出现在春季的 3～ 5月份 ,月平均浓度最低值为 4 87 5± 131 5× 10 -12 (体积分数 ) ;北京大气中CFC 11年平均浓度在观测时间段内呈先上升后下降的趋势 ,其中 1995～ 1998年增长较快 ,平均增长率为 17 9% ,1999年后呈缓慢下降趋势 ,平均下降率为 10 7% ,平均浓度是MaunaLoa全球基准观测站观测到大气本底CFC 11浓度的 3～ 5倍 .
In recent years, concentration of CFC in the atmosphere has undergone rapid changes especially in association with human activities. For the influence of CFC on climate changes and environment changes, the concentration of atmospheric CFC-11 in Beijing is continuously observed and analyzed by a gas chromatography-mass spectrometry.The seasonal variation concentration and trends of CFC-11 are reported. The results show that the seasonal variation of CFC-11 was basically similar from 1999 to 2003. There was one peak value in the seasonal variation of CFC-11 in 1999～2003. The highest monthly average concentration of CFC-11 was 1149.5±531.9×10 -12(V·V -1) in summer and the lowest monthly average concentration of CFC-11 was 487.5±131.5×10 -12(V·V -1) in spring. The annual average concentration of CFC-11 was increasing in Beijing atmosphere from 1995 to 1998, and the average increasing ratio was 17.9%. The annual average concentration of CFC-11 was slowly decreasing from 1999, and the average decreasing ratio was 10.7%. The average concentration of CFC-11 in the atmosphere of Beijing was 3～5 times of the average concentration of CFC-11 in the atmosphere of Mauna Loa Station of U.S.A.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2005年第1期1-6,共6页
Environmental Science
基金
国家自然科学基金项目 (4 0 2 2 2 2 0 2 )
中国科学院知识创新工程重大项目 (KZCX1 SW 0 1)
