Articles | Volume 12, issue 3
Atmos. Chem. Phys., 12, 1327–1338, 2012

Special issue: POLARCAT (Polar Study using Aircraft, Remote Sensing, Surface...

Atmos. Chem. Phys., 12, 1327–1338, 2012

Research article 02 Feb 2012

Research article | 02 Feb 2012

Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS

J. Liao1, L. G. Huey1, E. Scheuer2, J. E. Dibb1, R. E. Stickel1, D. J. Tanner1, J. A. Neuman3,4, J. B. Nowak3,4, S. Choi1, Y. Wang1, R. J. Salawitch5,6,7, T. Canty5, K. Chance8, T. Kurosu8,*, R. Suleiman8, A. J. Weinheimer9, R. E. Shetter9, A. Fried10, W. Brune11, B. Anderson12, X. Zhang1, G. Chen12, J. Crawford12, A. Hecobian1, and E. D. Ingall1 J. Liao et al.
  • 1School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
  • 2Institute for the Study of Earth, Oceans and Space, University of New Hampshire, Durham, NH, USA
  • 3Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA
  • 4Earth System Research Laboratory, NOAA, Boulder, Colorado, USA
  • 5Department of Atmospheric and Oceanic Science, University of Maryland, College Park, Maryland, USA
  • 6Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, USA
  • 7Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland, USA
  • 8Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
  • 9Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, Colorado, USA
  • 10Institute for Arctic and Alpine Research, University of Colorado, Boulder, CO, USA
  • 11Department of Meteorology, Pennsylvania State University, University Park, PA, USA
  • 12NASA Langley Research Center, Hampton, VA, USA
  • *now at: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA

Abstract. A focus of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was examination of bromine photochemistry in the spring time high latitude troposphere based on aircraft and satellite measurements of bromine oxide (BrO) and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometer (CIMS) to measure BrO and a mist chamber (MC) to measure soluble bromide. We have determined that the MC detection efficiency to molecular bromine (Br2), hypobromous acid (HOBr), bromine oxide (BrO), and hydrogen bromide (HBr) as soluble bromide (Br) was 0.9±0.1, 1.06+0.30/−0.35, 0.4±0.1, and 0.95±0.1, respectively. These efficiency factors were used to estimate soluble bromide levels along the DC-8 flight track of 17 April 2008 from photochemical calculations constrained to in situ BrO measured by CIMS. During this flight, the highest levels of soluble bromide and BrO were observed and atmospheric conditions were ideal for the space-borne observation of BrO. The good agreement (R2 = 0.76; slope = 0.95; intercept = −3.4 pmol mol−1) between modeled and observed soluble bromide, when BrO was above detection limit (>2 pmol mol−1) under unpolluted conditions (NO<10 pmol mol−1), indicates that the CIMS BrO measurements were consistent with the MC soluble bromide and that a well characterized MC can be used to derive mixing ratios of some reactive bromine compounds. Tropospheric BrO vertical column densities (BrOVCD) derived from CIMS BrO observations compare well with BrOTROPVCD from OMI on 17 April 2008.

Final-revised paper