Abstract
Abstract. As precursors to tropospheric ozone and nitrate, nitrogen oxide (NOx) in the present atmosphere and its transformation in response to emission and climate perturbations are studied by using the CAM-Chem model and air quality measurements from the National Emissions Inventory (NEI), Clean Air Status and Trends Network (CASTNET), and Environmental Protection Agency Air Quality System (EPA AQS). It is found that NOx transformations in present atmospheric conditions show different sensitivities over industrial and non-industrial regions. As a result, the surface ozone and nitrate formations can be divided into several regimes associated with the dominant emission types and relative levels of NOx and volatile organic compounds (VOC). Ozone production in industrial regions (the main NOx emission source areas) increases in warmer conditions and slightly decreases following an increase in NOx emissions due to NOx titration, which is opposite to the response in non-industrial regions. The ozone decrease following a temperature increase in non-industrial regions indicates that ozone production in regions that lack NOx emission sources may be sensitive to NOx transformation in remote source regions. The increase in NO2 from NOx titration over industrial regions results in an increase rate of total nitrate that remains higher than the increase rate of NOx emissions. The presented findings indicate that a change in the ozone concentration is more directly affected by changes in climate and precursor emissions, while a change in the nitrate concentration is affected by local ozone production types and their seasonal transfer. The sensitivity to temperature perturbations shows that a warmer climate accelerates the decomposition of odd nitrogen (NOy) during the night. As a result, the transformation rate of NOx to nitrate decreases. Examinations of the historical emissions and air quality records of a typical NOx-limited area, such as Atlanta and a VOC-limited area, such as Los Angeles further confirm the conclusions drawn from the modeling experiments.
Reference32 articles.
1. Aw, J. and Kleeman, M. J.: Evaluating the first-order effect of intra-annual temperature variability on urban air pollution, J. Geophys. Res., 108, 4365, https://doi.org/10.1029/2002JD002688, 2003.
2. Becker, J. G. and Graves, R. E.: Ammonia emissions and animal agriculture. In Proceedings Mid-Atlantic Agricultural Ammonia Forum. Woodstock, VA, 2004.
3. Blanchard, C. L. and Hidy, G. M.: Effects of changes in sulfate ammonia and nitric acid on particulate nitrate concentrations in the southeastern United States, J. Air Waste Manage. Assoc., 53, 283–290, 2003.
4. Blanchard, C. L., Hidy, G. M., Tanenbaum, S., Rasmussen, R., Watkins, R., and Edgerton, E.: NMOC, ozone, and organic aerosol in the southeastern United States, 1999–2007: 1. Spatial and temporal variations of NMOC concentrations and composition in Atlanta, Georgia, Atmos. Environ., 44, 4827–4839, 2010.
5. Blanchard, C. L., Tanenbaum, S., and Hidy, G. M.: Source contributions to atmospheric gases and particulate matter in the southeastern United States, Environ. Sci. Technol., 46, 5479–5488, 2012.
Cited by
12 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献