塔克拉玛干沙漠腹地冬季近地层CO2浓度变化特征

利用Li-8150系统在塔克拉玛干沙漠腹地进行了冬季近地层(￡6m)CO2浓度数据收集,结合同步气象资料,分析了近地层CO2浓度变化特征,土壤呼吸速率及气温、风速等气象因素对其变化特征的影响.结果表明,近地层CO2浓度日变化曲线呈单峰型结构,白天浓度高于夜晚.沙漠腹地冬季近地层大气CO2浓度主要集中分布在371.6~387.1μmol/mol,日平均最高值出现在12:00,最低值出现在凌晨;近地层CO2浓度对土壤呼吸速率的响应程度较好;不同高处气温与CO2浓度均存在着显著的正相关关系;近地层(31m)的CO2浓度受风速变化影响较大,而风速对0.5m及以下高度CO2浓度分布特征的影响相对较小;流动沙漠腹地,土壤呼吸和微弱的气象条件相互作用,共同调节和控制着近地层CO2的浓度变化.

Variation characteristics of atmospheric CO2 concentration of surface layer over the hinterland of Taklimakan Desert in winter

By using Li-8150 automated soil CO2 flux system and gradient tower system over the hinterland of Taklimakan Desert, this paper collected surface layer atmospheric CO2 profiles data and meteorological data in winter, which analyzed the variation characteristics of surface layer atmospheric CO2 concentration. The results showed that variation of surface layer CO2 concentration took on single peak curve and the mean CO2 concentration of daytime was higher than night; The daily variation of CO2 concentration ranged from 371.6μmol/mol to 387.1μmol/mol; The surface layer CO2 concentration had good response to soil respiration and also showed significant positive correlation with air temperature; The wind speed was notable to CO2 concentration at 1m above surface layer, but relatively not at 0.5m level above surface layer; CO2 concentration were jointly controlled by soil respiration and weak meteorological conditions over the hinterland of Taklimakan Desert.