Perchlorate in stratospheric aerosol particles
Abstract
Perchlorate is a toxic, regulated contaminant in drinking water. According to previous isotopic studies, much of the perchlorate deposited to the Earth’s surface is formed in the atmosphere, with 36 Cl suggesting a large contribution from the stratosphere. Here, we present measurements of perchlorate in stratospheric aerosol particles and confirm that the stratosphere is an important source of perchlorate, whereas we did not observe production in the troposphere. Mass mixing ratios of aerosol perchlorate in the stratosphere were 1 to 10 parts per trillion by mass (pptm), with the highest concentrations observed in summer and in the Southern Hemisphere. Almost all of the perchlorate is in biomass burning and nitrogen-rich particles, despite those types contributing only a few percent of the aerosol particles. Such particles are less acidic than the majority of sulfuric acid particles. If the formation of perchlorate is sensitive to acidity, then the injection of some materials for solar radiation modification might significantly increase the global production of perchlorate.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (16)
Daniel M. Murphy
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Maya Abou-Ghanem
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Adam T. Ahern
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Charles A. Brock
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Daniel J. Cziczo
Department of Earth, Atmospheric, and Planetary Sciences, Purdue University
Eric J. Hintsa
Cooperative Institute for Research in Environmental Sciences, University of Colorado
Justin L. Jacquot
Department of Earth, Atmospheric, and Planetary Sciences, Purdue University
Michael J. Lawler
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Ming Lyu
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Fred L. Moore
Cooperative Institute for Research in Environmental Sciences, University of Colorado
Michael A. Robinson
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
James M. Roberts
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Gregory P. Schill
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Xiaoli Shen
Department of Earth, Atmospheric, and Planetary Sciences, Purdue University
Troy D. Thornberry
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration
Patrick R. Veres
Chemical Sciences Laboratory, National Oceanic and Atmospheric Administration