Temporal variations of local traffic CO2 emissions and its relationship with CO2 flux in Beijing, China

Abstract Cities are the main source of CO 2 . Traffic is one of the most important sources of CO 2 emissions in urban areas. One-year CO 2 flux and 36-days traffic flow data were collected by field monitoring in 2014 at the study area. The accurate traffic CO 2 emissions on 30-min scale were calculated by the localized MOVES model. The annual emissions were 4139.19 Mg. The traffic CO 2 emissions showed a “double-peak” diurnal pattern, with morning peak of 705.14 kg 30 min −1 (8:00–8:30) and the evening peak of 788.40 kg/30 min −1 (7:30–18:00). The tail number limited measure in Beijing has reached certain extent, with emissions by limited tail number as follows: 1 or 6 (11.03 Mg/d)  2 emissions and CO 2 flux is modified from the perspective of spatial boundary definition and unit unification. Traffic CO 2 emissions had significantly positive effects on the CO 2 flux. The absolute values of the standard coefficients were in the following order: for the whole year in 2014, temperature (−0.316) > radiation (−0.152) > traffic CO 2 emissions (0.107); for the plant growing season, radiation (−0.254) > temperature (−0.130) > traffic CO 2 emissions (0.105).