中国大陆对流层大气中甲烷（CH4）浓度的背景特征研究

随着近10年来全球某些地区气候变暖趋势的日益明显,对大气层温室效应及其有关主要温室性气体CO_2,CH_4,N_2O,O_3,CFCs的研究受到前所未有的重视。这些大气微量成分在对流层的增长趋势已被确认,对其分布特征,变化趋势、源和汇的研究都获得重要进展。就CH_4而言,通过对南极和格陵兰积冰冰芯中残留空气CH_4浓度的测定,发现从1771年到1955年大气CH_4浓度从0.78±0.09 ppmv上升到1.30±0.07 ppmv。仅80年代就增加了约15％,年增长率为10—16 ppbv。近年来的全球烧

A STUDY OF THE BACKGROUND CHARACTERS OF CH4 CONCENTRATION IN TROPOSPHERE OVER THE CONTINENT OF CHINA

The distribution of CH,background concentration in the troposphere and the characteristics of it's variation with latitude,season and elevation were discussed at sampling range of 30-450N,88-1380E in China during the period July 1988 to May 1990.The values of CH9 concentration decreased as the altitude increased,and increased as the latitude increased.Through measurement of air samples collected weekly,it is found that there was significant seasonal variation at the Lu Shan mountain and Wutai Shan mountain in April 1989 to May 1990.The lower values appeared in the Summer.The higher values arose in the end of spring and early autumn.By using samples collected in the aeroplane,a vertical gradient was observed between earth's surface and the height of 4000 metres (m) over Gubantiinggiit desert at Xinjiang in November 1989.