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Atmos. Chem. Phys. Discuss., 11, 26999-27030, 2011
www.atmos-chem-phys-discuss.net/11/26999/2011/ doi:10.5194/acpd-11-26999-2011 © Author(s) 2011. This work is distributed under the Creative Commons Attribution 3.0 License. |
Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS
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
6Deptartment 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
10Department of meteorology, Pennsylvania State University, University Park, PA, USA
11NASA Langley Research Center, Hampton, VA, 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 BrO and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometry (CIMS) instrument 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, 0.4±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 = 0.98; intercept = −3.5 pptv) between modeled and observed soluble bromide, when BrO was above detection limit (>2 pptv) under unpolluted conditions (NO < 100 pptv), indicates that the CIMS BrO measurements were consistent with the MC soluble bromide. Tropospheric BrO vertical column densities (BROTROPVCD) derived from CIMS BrO observations compare well with BROTROPVCD from OMI on 17 April 2008.
Citation: Liao, J., Huey, L. G., Scheuer, E., Dibb, J. E., Stickel, R. E., Tanner, D. J., Neuman, J. A., Nowak, J. B., Choi, S., Wang, Y., Salawitch, R. J., Canty, T., Chance, K., Kurosu, T., Suleiman, R., Weinheimer, A. J., Shetter, R. E., Fried, A., Brune, W., Anderson, B., Zhang, X., Chen, G., Crawford, J., Hecobian, A., and Ingall, E. D.: Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS, Atmos. Chem. Phys. Discuss., 11, 26999-27030, doi:10.5194/acpd-11-26999-2011, 2011.