In this study, air pollutants, including ozone (O₃), nitrogen oxides (NOx = NO + NO₂), carbon monoxides (CO), sulfur dioxide (SO₂), and volatile organic compounds (VOCs) measured in the Yangtze River Delta (YRD) region during several air flights between September/30 and October/11 are analyzed. T... Show moreIn this study, air pollutants, including ozone (O₃), nitrogen oxides (NOx = NO + NO₂), carbon monoxides (CO), sulfur dioxide (SO₂), and volatile organic compounds (VOCs) measured in the Yangtze River Delta (YRD) region during several air flights between September/30 and October/11 are analyzed. This measurement provides horizontal and vertical distributions of air pollutants in the YRD region. The analysis of the result shows that the measured O₃ concentrations range from 20 to 60 ppbv. These values are generally below the US national standard (84 ppbv), suggesting that at the present, the O₃ pollutions are modest in this region. The NOx concentrations have strong spatial and temporal variations, ranging from 3 to 40 ppbv. The SO₂ concentrations also have large spatial and temporal variations, ranging from 1 to 35 ppbv. The high concentrations of CO are measured with small variations, ranging from 3 to 7 ppmv. The concentrations of VOCs are relatively low, with the total VOC concentrations of less than 6 ppbv. The relative small VOC concentrations and the relative large NOx concentrations suggest that the O₃ chemical formation is under a strong VOC-limited regime in the YRD region. The measured O₃ and NOx concentrations are strongly anti-correlated, indicating that enhancement in NOx concentrations leads to decrease in O₃ concentrations. Moreover, the O₃ concentrations are more sensitive to NOx concentrations in the rural region than in the city region. The ratios of Δ [O₃]/Δ [NOx] are -2.3 and -0.25 in the rural and in the city region, respectively. In addition, the measured NOx and SO₂ concentrations are strongly correlated, highlighting that the NOx and SO₂ are probably originated from same emission sources. Because SO₂ emissions are significantly originated from coal burnings, the strong correlation between SO₂ and NOx concentrations suggests that the NOx emission sources are mostly from coal burned sources. As a result, the future automobile increases could lead to rapid enhancements in O₃ concentrations in the YRD region. Show less
