长江三角洲2018年土壤NO排放特征

土壤是大气一氧化氮（NO）重要的来源之一，在大气化学中起着重要的作用.基于最新的BDSNP算法构建长三角地区2018年土壤NO排放清单，并进一步分析其时空特征和不确定性.结果表明，长三角地区2018年土壤NO排放量为213.6 kt,占人为源NO_x排放总量的7.3%,排放高值区主要集中在安徽省北部和江苏省大部分地区.从月变化来看，土壤NO排放在6月达到峰值，占全年排放的19.9%,占6月人为源NO_x排放量的19.7%;从小时变化来看，土壤NO排放在16:00点达到峰值，占全天的5.5%.土壤NO排放包括土壤本底、氮肥施用和氮沉降这3个部分；氮肥施用是土壤NO排放的主要来源，占比高达77.8%.随着机动车和工业等NO_x排放的深入减排，土壤NO排放的重要性将日益凸显.

Characteristics of Soil NO Emissions in the Yangtze River Delta Region for Year 2018

Soil NO emissions represent an important source of atmospheric nitric oxide (NO) and play an important role in atmospheric chemistry. Based on the latest BDSNP algorithm, this study estimated the soil NO emissions over the Yangtze River Delta region for the year 2018 and further analyzed the associated temporal and spatial variations and uncertainties. The results showed that the annual soil NO emissions in 2018 over the YRD region was 213.6 kt, accounting for 7.3% of the total anthropogenic NO_x emissions. Areas with high emissions were mainly concentrated in northern Anhui Province and most parts of Jiangsu Province. In terms of monthly variations, soil NO emissions peaked in June, accounting for 19.9% of the annual emissions and 19.7% of anthropogenic NO_x emissions in June. In terms of daily variations, soil NO emissions peaked around 16:00 and accounted for 5.5% of daily emissions. Soil NO emissions came from three components:soil background, nitrogen fertilizer application, and nitrogen deposition. Nitrogen fertilizer application was the main source of soil NO emissions, accounting for up to 77.8%. With the in-depth reduction in NO_x emissions from motor vehicles and industries, the importance of soil NO emissions will become increasingly prominent.