Temporal characteristics of atmospheric ammonia and nitrogen dioxide over China based on emission data, satellite observations and atmospheric transport modeling since 1980
Lei Liu1, Xiuying Zhang1, Wen Xu2, Xuejun Liu2, Yi Li3, Xuehe Lu1, Yuehan Zhang4, and Wuting Zhang1,51Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China 2College of Resources and Environmental Sciences, Centre for Resources, Environment and Food Security, Key Lab of Plant-Soil Interactions of MOE, China Agricultural University, Beijing 100193, China 3Air Quality Division, Arizona Department of Environmental Quality, Phoenix, AZ, 85007, USA 4School of Atmospheric Sciences, Nanjing University, Nanjing, China 5Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China
Received: 03 Feb 2017 – Accepted for review: 15 Mar 2017 – Discussion started: 21 Mar 2017
Abstract. China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen (Nr). Atmospheric ammonia (NH3) and nitrogen dioxide (NO2) are the most important precursors for Nr compounds (including N2O5, HNO3, HONO and particulate NO3− and NH4+) in the atmosphere. Understanding the changes of NH3 and NO2 has important implications for the regulation of anthropogenic Nr emissions, and is a requirement for assessing the consequence of environmental impacts. We conducted the temporal trend analysis of atmospheric NH3 and NO2 on a national scale since 1980 based on emission data (during 1980–2010), satellite observations (for NH3 since 2008 and for NO2 since 2005) and atmospheric chemistry transport modeling (during 2008–2015).
Based on the emission data, during 1980–2010, both significant continuous increasing trend of NH3 and NOx were observed from REAS (Regional Emission inventory in Asia, for NH3 0.17 kg N ha−1 y−2 and for NOx 0.16 kg N ha−1 y−2) and EDGAR (Emissions Database for Global Atmospheric Research, for NH3 0.24 kg N ha−1 y−2 and for NOx 0.17 kg N ha−1 y−2) over China. Based on the satellite data and atmospheric chemistry transport modeling named as the Model for Ozone and Related chemical Tracers, version 4 (MOZART-4), the NO2 columns over China increased significantly (p<0.01) from 2005 to 2011 and then decreased significantly from 2011 to 2015; the satellite-retrieved NH3 columns from 2008 to 2014 had no big changes but increased in 2015 (large increase from satellite IASI, but slight increase from MOZART-4). The decrease in NO2 columns since 2011 may result from more stringent strategies taken to control NOx emissions during the 12th Five-Year-Plan, while no control policy focused on NH3 emissions. Our findings provided an overall insight on the temporal trends of both NO2 and NH3 since 1980 based on emission data, satellite observations and atmospheric transport modeling. These findings can provide a scientific background for policy-makers that are attempting to control atmospheric pollution in China. Moreover, the multivariate data used in this study have implications for estimating long-term Nr deposition datasets to assess its impact on soil, forest, water and greenhouse balance.
Liu, L., Zhang, X., Xu, W., Liu, X., Li, Y., Lu, X., Zhang, Y., and Zhang, W.: Temporal characteristics of atmospheric ammonia and nitrogen dioxide over China based on emission data, satellite observations and atmospheric transport modeling since 1980, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-106, in review, 2017.