A test study of atmospheric 14CO2 variations in southeastern Xi'an City

Δ14CO 2 observations via Accelerator mass spectrometer are increasingly used to trace recently added fossil fuel CO 2 in the atmosphere for evaluating and constraining the CO 2 emission. In this study, we collected one-day CO 2 samples in southeastern Xi'an City and analyzed them in the Xi'an-AMS Center to test our method. A TiH 2 graphitization method introduced by Dr. Xu was modified by us to graphitize the CO 2 samples for AMS measurement. Our preliminary results show that fossil fuel varied from 1.16%–8.36% of the CO 2 concentration in air at the southeastern Xi'an City. We concluded the large variations of the fossil fuel CO 2 concentration may be caused by motor vehicle exhaust emission and people daily coal burning.