Export of reactive nitrogen from coal‐fired power plants in the U.S.: Estimates from a plume‐in‐grid modeling study

Author: K. Vijayaraghavan, Y. Zhang, C. Seigneur, P. Karamchandani and Hilary E. "Ned" Snell
Date: 
December 31, 2009
Type: 
Journal Article
Venue: 
Journal of Geophysical Research
Citation: 

Vijayaraghavan, K., Y. Zhang, C. Seigneur, P. Karamchandani, and H. E. Snell (2009), Export of reactive nitrogen from coal‐fired power plants in the U.S.: Estimates from a plume‐in‐grid modeling study, J. Geophys. Res., 114, D04308, doi:10.1029/2008JD010432.

The export of reactive nitrogen (nitrogen oxides and their oxidation products, collectively referred to as NOy) from coal‐fired power plants in the U.S. to the rest of the world could have a significant global contribution to ozone. Traditional Eulerian gridded air quality models cannot characterize accurately the chemistry and transport of plumes from elevated point sources such as power plant stacks. A state‐of‐the‐science plume‐in‐grid (PinG) air quality model, a reactive plume model embedded in an Eulerian gridded model, is used to estimate the export of NOy from 25 large coal‐fired power plants in the U.S. (in terms of NOx and SO2 emissions) in July 2001 to the global atmosphere. The PinG model used is the Community Multiscale Air Quality Model with Advanced Plume Treatment (CMAQ‐APT). A benchmark simulation with only the gridded model, CMAQ, is also conducted for comparison purposes. The simulations with and without advanced plume treatment show differences in the calculated export of NOy from the 25 plants considered reflecting the effect of using a detailed and explicit treatment of plume transport and chemistry. The advanced plume treatment results in 31% greater simulated export of NOy compared to the purely grid‐based modeling approach. The export efficiency of NOy (the fraction of NOy emitted that is exported) is predicted to be 21% without APT and 27% with APT. When considering only export through the eastern boundary across the Atlantic, CMAQ‐APT predicts that the export efficiency is 24% and that 2% of NOy is exported as NOx, 49% as inorganic nitrate, and 25% as PAN. These results are in reasonably good agreement with an analysis reported in the literature of aircraft measurements over the North Atlantic.