太湖流域近地表大气二氧化碳本底体积分数观测研究

Study on the near-surface atmospheric carbon dioxide background concentration in Taihu Lake catchment

基于2003年1月至2005年6月用气相色谱法对太湖流域近地表大气中二氧化碳本底体积分数的监测资料,对太湖流域近地表大气二氧化碳体积分数的变化特征进行了分析研究。结果表明:在观测时段内,太湖流域近地表大气二氧化碳体积分数平均值为(413.7±19.2)×10-6,且呈上升的趋势,主要受人类活动、工农业生产和交通运输业发展的影响;二氧化碳体积分数季节变化明显,冬春季高,夏秋季低,冬季出现峰值,平均体积分数为(417.8±3.7)×10-6,夏季出现谷值,平均体积分数为(400.8±14.7)×10-6,一年中最高值(424.0±1.1)×10-6出现在12月份,最低值(387.7±1.4)×10-6出现在8月份,主要受源汇强度变化影响;二氧化碳体积分数日变化基本呈双峰态,这是源汇强度变化和边界层稳定程度相互作用的结果。

Based on the measurement of the near-surface atmospheric carbon dioxidebackground concentration from January 2003 to June 2005 in Taihu Lake catchment by using gas chromatography, Variation characteristics of the near-surface atmospheric carbon dioxide background concentration are analyzed. During the measurement period, it shows that the mean volume fraction of the near-surface atmospheric carbon dioxide is （413.7± 19.2）× 10^-6 and the concentration trends increasing, which is effected by the human activities and the development of industry, agriculture and transportation. Seasonal variation of the near-surface atmospheric carbon dioxide background concentration is obvious. It is high in winter and spring, and low in summer and autumn. The peak value, （417.8 ± 3.7）× 10^-6, appears in winter. And the valley value, （400,8 ± 14.7）× 10^-6, occurs in summer, In a year, the maximum （424.0 ± 1.1）×10^-6 appears in December, and the minimum （387.7 ± 1.4）×10^-6 occurs in August. It is mainly influenced under the intensity variation of sources and sinks. Diurnal variation takes on two-peak regularity, which is induced by the interactivity between intensity variations of sources and sinks and the stability degree of boundary layer.