Survey of Accumulation Mode Particulate Halogens (I, Br, Cl) over the Remote Atmosphere

DONGWOOK KIM, Pedro Campuzano-Jost, Benjamin A. Nault, Douglas A. Day, Michael Cubison, Jack Dibb, Yuk Chun Chan, Lyatt Jaegle, Thomas Ryerson, Alessandro Franchin, Eric Apel, Rebecca Hornbrook, Alan Hills, Donald Blake, Lee Mauldin, Yandong Tong, Rainer M. Volkamer, Jose-Luis Jimenez, University of Colorado, Boulder

     Abstract Number: 444
     Working Group: Remote and Regional Atmospheric Aerosol

Abstract
Halogens play important roles in ozone chemistry in both the stratosphere and troposphere. Bromine can affect the deposition rate of mercury in the atmosphere. Particulate halogens can react directly with ozone and could serve as reservoirs for gas-phase reactive halogen species. However, quantitative measurements of particulate halogens on a global scale over remote areas are rare, especially in the upper troposphere and the lower stratosphere. Here we report particulate halogen measurements (iodine, bromine, chloride, and perchlorate) with a customized University of Colorado high-resolution aerosol mass spectrometer (CU-HR-AMS) from multiple aircraft campaigns, including the NASA ATom missions and the NSF TI³GER campaign. In this study, we present a global overview of particulate halogen distribution over the remote atmosphere. We also discuss 1) AMS response to particulate halogens and quantification method, 2) particulate halogen measurement intercomparison, and 3) episodes of the enhancements of iodine and perchlorate near the tropopause and their implications for ozone chemistry in the stratosphere. These results will provide valuable constraints on the halogen budget and chemistry in chemical transport models.

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