Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 9, 2009 | Published
Journal Article Open

Effect of changes in climate and emissions on future sulfate-nitrate-ammonium aerosol levels in the United States


Global simulations of sulfate, nitrate, and ammonium aerosols are performed for the present day and 2050 using the chemical transport model GEOS-Chem. Changes in climate and emissions projected by the IPCC A1B scenario are imposed separately and together, with the primary focus of the work on future inorganic aerosol levels over the United States. Climate change alone is predicted to lead to decreases in levels of sulfate and ammonium in the southeast U.S. but increases in the Midwest and northeast U.S. Nitrate concentrations are projected to decrease across the U.S. as a result of climate change alone. In the U.S., climate change alone can cause changes in annually averaged sulfate-nitrate-ammonium of up to 0.61 μg/m^3, with seasonal changes often being much larger in magnitude. When changes in anthropogenic emissions are considered (with or without changes in climate), domestic sulfate concentrations are projected to decrease because of sulfur dioxide emission reductions, and nitrate concentrations are predicted to generally increase because of higher ammonia emissions combined with decreases in sulfate despite reductions in emissions of nitrogen oxides. The ammonium burden is projected to increase from 0.24 to 0.36 Tg, and the sulfate burden to increase from 0.28 to 0.40 Tg S as a result of globally higher ammonia and sulfate emissions in the future. The global nitrate burden is predicted to remain essentially constant at 0.35 Tg, with changes in both emissions and climate as a result of the competing effects of higher precursor emissions and increased temperature.

Additional Information

© 2009 American Geophysical Union. Received 1 July 2008; revised 22 September 2008; accepted 7 October 2008; published 9 January 2009. This work was supported by the U.S. Environmental Protection Agency's STAR Program (grants RD830959 and RD833370). Havala Pye was supported by a National Science Foundation Graduate Research Fellowship. Hong Liao acknowledges the support from National Natural Science Foundation of China (grant 40775083). We would like to acknowledge the Clean Air Status and Trends Network (CASTNET). Discussions with Becky Alexander, Athanasios Nenes, Yang Zhang, and Donald Dabdub are greatly appreciated.

Attached Files

Published - PYEjgrd09.pdf


Files (1.5 MB)
Name Size Download all
1.5 MB Preview Download

Additional details

August 20, 2023
October 17, 2023