Articles | Volume 12, issue 10
Atmos. Chem. Phys., 12, 4429–4447, 2012
Atmos. Chem. Phys., 12, 4429–4447, 2012

Research article 21 May 2012

Research article | 21 May 2012

Growth in NOx emissions from power plants in China: bottom-up estimates and satellite observations

S. W. Wang1, Q. Zhang2, D. G. Streets3, K. B. He1, R. V. Martin4,5, L. N. Lamsal6,7, D. Chen8, Y. Lei9, and Z. Lu3 S. W. Wang et al.
  • 1State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
  • 2Ministry of Education Key Laboratory for Earth System Modeling, Center for Earth System Science, Tsinghua University, Beijing, China
  • 3Decision and Information Sciences Division, Argonne National Laboratory, Argonne, IL, USA
  • 4Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada
  • 5Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
  • 6Goddard Earth Sciences Technology and Research, Universities Space Research Association, Columbia, MD, USA
  • 7NASA Goddard Space Flight Center, Greenbelt, MD, USA
  • 8Department of Atmospheric and Oceanic Sciences, University of California at Los Angeles, Los Angeles, CA, USA
  • 9Key Laboratory of Environmental Planning and Policy Simulation, Chinese Academy for Environmental Planning, Beijing, China

Abstract. Using OMI (Ozone Monitoring Instrument) tropospheric NO2 columns and a nested-grid 3-D global chemical transport model (GEOS-Chem), we investigated the growth in NOx emissions from coal-fired power plants and their contributions to the growth in NO2 columns in 2005–2007 in China. We first developed a unit-based power plant NOx emission inventory for 2005–2007 to support this investigation. The total capacities of coal-fired power generation have increased by 48.8% in 2005–2007, with 92.2% of the total capacity additions coming from generator units with size ≥300 MW. The annual NOx emissions from coal-fired power plants were estimated to be 8.11 Tg NO2 for 2005 and 9.58 Tg NO2 for 2007, respectively. The modeled summer average tropospheric NO2 columns were highly correlated (R2 = 0.79–0.82) with OMI measurements over grids dominated by power plant emissions, with only 7–14% low bias, lending support to the high accuracy of the unit-based power plant NOx emission inventory. The ratios of OMI-derived annual and summer average tropospheric NO2 columns between 2007 and 2005 indicated that most of the grids with significant NO2 increases were related to power plant construction activities. OMI had the capability to trace the changes of NOx emissions from individual large power plants in cases where there is less interference from other NOx sources. Scenario runs from GEOS-Chem model suggested that the new power plants contributed 18.5% and 10% to the annual average NO2 columns in 2007 in Inner Mongolia and North China, respectively. The massive new power plant NOx emissions significantly changed the local NO2 profiles, especially in less polluted areas. A sensitivity study found that changes of NO2 shape factors due to including new power plant emissions increased the summer average OMI tropospheric NO2 columns by 3.8–17.2% for six selected locations, indicating that the updated emission information could help to improve the satellite retrievals.

Final-revised paper