JpGU-AGU Joint Meeting 2020

Presentation information

[E] Poster

A (Atmospheric and Hydrospheric Sciences ) » A-AS Atmospheric Sciences, Meteorology & Atmospheric Environment

[A-AS04] Formation of Air Pollution and Its Interactions with Weather/Climate

convener:Yang Yang(Nanjing University of Information Science & Technology), Meng Gao(State Key Laboratory of Environmental and Biological Analysis), Guangxing Lin(Pacific Northwest National Laboratory)

[AAS04-P04] Spatiotemporal variations of recent NO2 concentrations and anthropogenic and meteorological drivers over typical urban agglomerations in China

*Yang Shen1, Fei Jiang1 (1.Nanjing University)

Keywords:NO2, urban agglomeration, spatiotemporal pattern, WRF−CMAQ, quantitative impact

Nitrogen dioxide (NO2) is an important pollution gas that can affect air quality and human health. In this study, spatiotemporal distribution of NO2 concentrations throughout China, and specifically in twelve typical urban agglomerations, were statistically analyzed with ground−based NO2 observations from June 2014 to May 2019. The WRF−CMAQ model were also applied to separate and quantify the emission−related and meteorology−related NO2 variations. NO2 concentration in Beijing−Tianjin−Hebei (BTH) urban agglomeration showed an upward trend in 2014−2015, and a downward trend after 2016, while NO2 in Yangtze River Delta (YRD), Yangtze River Middle−Reach (YRMR) and Cheng−Yu (CY) urban agglomerations continued to decline until 2017. High NO2 values were predominantly concentrated in urban agglomerations with high NOx emissions like BTH, Shandong Peninsula (SP), Central Plain (CP), Central Shaanxi (CS) and YRD urban agglomeration. The number of sites with NO2 decreasing in 2018 accounts for 67.37% compared to 2015, especially in BTH and CP, with the decrease of more than 20 μg·m−3. High−high concentration centers of NO2 pollution were observed in high NO2 areas, while low−low aggregations were observed in the South and southwest of China. In general, anthropogenic emissions contributed dominantly to NO2 variations, and the contribution in winter was greater than in summer. The reduction of emissions in the winter of 2018 led to emission−related NO2 variations in YRD, YRMR, CY, and Pearl River Delta (PRD) urban agglomeration reaching −7.41, −9.15, −9.57, and −15.09 μg·m−3, respectively. While in the winter of BTH, meteorological influence on NO2 was more obvious than that of other regions, leading variations of 4.42, 4.09, −9.77, and 5.99 μg·m−3, respectively between 2014 and 2018 in adjacent years. This study makes it possible to look into the differences in NO2 concentrations among typical urban agglomerations and provide a more complete understanding of NO2 exposures in China.