Seasonal Variation of CO2 Vertical Distribution in the Atmospheric Boundary Layer and Impact of Meteorological Parameters

This paper presents the seasonality of vertical profiles of CO 2 within 0–1100 m at a suburban site and discussions on the impacts of meteorological parameters on it. CO 2 concentrations as well as metrological conditions were measured on June 2–18, July 7–22 (21 days, summer), October 10–20 (10 days, autumn) in 2012, and January 15–February 1 (12 days, winter), May 7–23 (10 days, spring) in 2013. The CO 2 vertical profiles were affected by meteorological conditions, source emissions, urban canopy and other factors. The CO 2 concentrations’ comparison analysis between different seasons including spring, summer (previously published results), autumn and winter suggests that the highest peak of the CO 2 concentration (450.00 ± 14.78 ppm) occurred during winter (2013-01-23 at 09:00–09:55) with neutral stability class whereas the lowest peak of the CO 2 concentration (389.88 ± 4.67 ppm) occurred during summer (2012-07-17 at 15:48–16:40) with moderately stable conditions. The high levels of CO 2 concentrations were due to the accumulation caused by the stable atmosphere dominant during the measurement period. Atmospheric CO 2 concentrations in summer can be lower near the surface than at elevated altitude under certain conditions because terrestrial photosynthesis dominated the industrial pollutant emissions at that time. However, in other seasons, CO 2 profiles showed monotonically declining trends with altitudes.