Characterization of spatial and temporal distribution of NH3 concentrations and emissions in China based on IASI observations
Based on the NH3 column concentration data inverted by the infrared atmospheric sounding interferometer(IASI),the NH3 emissions in China from 2008 to 2016 were estimated using an emission flux box model and dynamic NH3 lifetimes.Then,the spatial distribution and long-term trends of NH3 concentrations and emissions in China were analyzed by combining land cover types,population density and population growth in China.The results indicated that the average column concentration,the emission flux density,and the emissions of NH3 in China from 2008 to 2016 were 6.81×1015 molec/cm2,1.43g/m2,and 10.09 Tg,respectively.The concentrations of NH3 in Shandong and Henan provinces increased the fastest,with average annual growth rates of 1.47×1015 and 1.23×1015 molec/(cm2·a),respectively.The high concentration and high emission intensity mainly appeared in North China,central Xinjiang and the Sichuan basin,showing a decreasing trend from center to periphery,which is basically consistent with the distribution of China's arable land and high-population-density areas.The overall NH3 emissions in China showed an upward trend,increasing from 9.33 Tg in 2008 to 13.96 Tg in 2016,and increased from 4.96％to 24.88％of the global emissions.During this period,the northwestern and northern regions of China contributed 47.50％of the total emissions,while the Tibetan Plateau region accounted for only 2.65％.The NH3 concentration in China has the seasonal characteristic of"high in summer and low in winter",and each season accounts for 28.96％,49.84％,13.02％and 8.17％of the total annual concentration,respectively,which indicates that the contribution of frequent agricultural activities and fertilizer application to NH3 concentration in spring and summer cannot be ignored.The NH3 concentrations and emissions show significant spatiotemporal differences in China,thus preparation of air pollution control plans for different periods of time and regions will be more effective in reducing NH3 emissions.
NH3 emissionsinfrared atmospheric sounding interferometer(IASI)NH3 lifetimePM2.5 pollutionspatial and temporal distribution
万方数据
