摘要
The level of atmosphericΔ14C and the fossil fuel derived CO 2 concentration in the Beijing area from May to September,2009, were systematically analyzed based on radiocarbon(14C)measurements of annual plants by accelerator mass spectrometry(AMS). The results show that the maximumΔ14C in Beijing was 29.6‰±2.2‰,and the minimum was–28.2‰±2.5‰,with a trend of decreasingΔ14C from the outer suburbs to inner suburbs to the urban center.This trend correlates well with increases in fossil fuel derived CO2 caused by human activities such as population density,industrial emissions and traffic,with lower values of atmosphericΔ14C associated with more intensive human activities.The fossil fuel derived CO 2 concentrations from May to September, 2009,ranged from 3.9±1.0 ppm to 25.4±1.0 ppm.It was calculated that each additional 1 ppm of CO2 from fossil fuels depleted the atmosphericΔ14C by approximately 2.70‰.This study suggests that 14C measurements of annual plants by AMS provide an effective method to rapidly trace fossil fuel derived CO2.
The level of atmospheric △14C and the fossil fuel derived CO2 concentration in the Beijing area from May to September, 2009, were systematically analyzed based on radiocarbon （14C） measurements of annual plants by accelerator mass spectrometry （AMS）. The results show that the maximum Alga in Beijing was 29.6‰±2.2‰, and the minimum was -28.2‰±2.5‰, with a trend of decreasing At4C from the outer suburbs to inner suburbs to the urban center. This trend correlates well with increases in fossil fuel derived CO2 caused by human activities such as population density, industrial emissions and traffic, with lower values of atmospheric △14C associated with more intensive human activities. The fossil fuel derived CO2 concentrations from May to September, 2009, ranged from 3.9±1.0 ppm to 25.4±1.0 ppm. It was calculated that each additional 1 ppm of CO2 from fossil fuels depleted the atmospheric △14C by approximately 2.70‰. This study suggests that 14C measurements of annual plants by AMS provide an effective method to rapidly trace fossil fuel derived CO2.
