References

ACP

Atmospheric Chemistry and Physics

ACP

1680-7324

Copernicus GmbH

Göttingen, Germany

10.5194/acp-12-10833-2012

Overview of the 2007 and 2008 campaigns conducted as part of the Greenland Summit Halogen-HOx Experiment (GSHOX)

Thomas

J. L.

¹ ² Dibb

J. E.

³ Stutz

¹ von Glasow

⁴ Brooks

⁵ Huey

L. G.

⁶ Lefer

⁷

Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, CA 90095, USA

UPMC Univ. Paris 06, UMR8190, CNRS/INSU – Univ. Versailles St.-Quentin, LATMOS-IPSL, Paris, France

Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA

School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK

NOAA ATDD, 456 S. Illinois Ave, P.O. Box 2456, Oak Ridge, TN 38731, USA

School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30033, USA

Department of Geosciences, University of Houston, TX 77204, USA

16 11 2012

12 22 10833 10839

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From 10 May through 17 June 2007 and 6 June through 9 July 2008 intensive sampling campaigns at Summit, Greenland confirmed that active bromine chemistry is occurring in and above the snow pack at the highest part of the Greenland ice sheet (72°36´ N, 38°25´ W and 3.2 km above sea level). Direct measurements found BrO and soluble gas phase Br− mixing ratios in the low pptv range on many days (maxima < 10 pptv). Conversion of up to 200 pg m−3 of gaseous elemental mercury (GEM) to reactive gaseous mercury (RGM) and enhanced OH relative to HO2 plus RO2 confirm that active bromine chemistry is impacting chemical cycles even at such low abundances of reactive bromine species. However, it does not appear that Bry chemistry can fully account for observed perturbations to HOx partitioning, suggesting unknown additional chemical processes may be important in this unique environment, or that our understanding of coupled NOx-HOx-Bry chemistry above sunlit polar snow is incomplete. Rapid transport from the north Atlantic marine boundary layer occasionally caused enhanced BrO at Summit (just two such events observed during the 12 weeks of sampling over the two seasons). In general observed reactive bromine was linked to activation of bromide (Br−) in, and release of reactive bromine from, the snowpack. A coupled snow-atmosphere model simulated observed NO and BrO at Summit during a three day interval when winds were weak. The source of Br− in surface and near surface snow at Summit is not entirely clear, but concentrations were observed to increase when stronger vertical mixing brought free tropospheric air to the surface. Reactive Bry mixing ratios above the snow often increased in the day or two following increases in snow concentration, but this response was not consistent. On seasonal time scales concentrations of Br− in snow and reactive bromine in the air were directly related.

References 1

Brooks, S., Moore, C., Lew, D., Lefer, B., Huey, G., and Tanner, D.: Temperature and sunlight controls of mercury oxidation and deposition atop the Greenland ice sheet, Atmos. Chem. Phys., 11, 8295–8306, http://dx.doi.org/10.5194/acp-11-8295-2011doi:10.5194/acp-11-8295-2011, 2011.

Chen, G., Huey, L. G., Crawford, J. H., Olsen, J. R., Hutterli, M. A., Sjostedt, S., Tanner, D., Dibb, J., Lefer, B., Blake, N., Davis, D., and Stohl, A.: An assessment of the the polar HO$_\mathrmx$ budget based on 2003 Summit Greenland field observations, Atmos. Environ., 41, 7806–7828, http://dx.doi.org/10.1016/j.atmosenv.2007.06.014doi:10.1016/j.atmosenv.2007.06.014, 2007.

Choi, S., Wang, Y., Salawitch, R. J., Canty, T., Joiner, J., Zeng, T., Kurosu, T. P., Chance, K., Richter, A., Huey, L. G., Liao, J., Neuman, J. A., Nowak, J. B., Dibb, J. E., Weinheimer, A. J., Diskin, G., Ryerson, T. B., da Silva, A., Curry, J., Kinnison, D., Tilmes, S., and Levelt, P. F.: Analysis of satellite-derived Arctic tropospheric BrO columns in conjunction with aircraft measurements during ARCTAS and ARCPAC, Atmos. Chem. Phys., 12, 1255–1285, http://dx.doi.org/10.5194/acp-12-1255-2012doi:10.5194/acp-12-1255-2012, 2012.

Davis, D., Nowak, J. B., Chen, G., Buhr, M., Arimoto, R., Hogan, A., Eisele, F., Mauldin, L., Tanner, D., Shetter, R., Lefer, B., and McMurry, P.: Unexpected high levels of NO observed at South Pole, Geophys. Res. Lett., 28, 3625–3628, 2001.

Dibb, J. E.: Vertical mixing above Summit, Greenland: Insights into seasonal and high frequency variability from the radionuclide tracers $^7$Be and $^210$Pb, Atmos. Environ., 41, 5020–5030, http://dx.doi.org/10.1016/j.atmosenv.2006.12.005doi:10.1016/j.atmosenv.2006.12.005, 2007.

Dibb, J. E., Albert, M., Courville, Z., Anastasio, C., Galbavy, E. S., Atlas, E., Beyersdorf, A. J., Blake, D. R., Meinardi, S., Rowland, F. S., Swanson, A. L., Blake, N. J., Bocquet, F., Cohen, L., Helmig, D., Burkhart, J. F., Frey, M. M., Friel, D. K., Hutterli, M. A., Chen, G., Conway, T. J., and Oltmans, S. J.: An overview of air-snow exchange at Summit, Greenland: recent experiments and findings, Atmos. Environ., 41, 4995–5006, http://dx.doi.org/10.1016/j.atmosenv.2006.12.006doi:10.1016/j.atmosenv.2006.12.006, 2007.

Dibb, J. E., Ziemba, L. D., Luxford, J., and Beckman, P.: Bromide and other ions in the snow, firn air, and atmospheric boundary layer at Summit during GSHOX, Atmos. Chem. Phys., 10, 9931–9942, http://dx.doi.org/10.5194/acp-10-9931-2010doi:10.5194/acp-10-9931-2010, 2010.

Grannas, A. M., Jones, A. E., Dibb, J., Ammann, M., Anastasio, C., Beine, H. J., Bergin, M., Bottenheim, J., Boxe, C. S., Carver, G., Chen, G., Crawford, J. H., Dominé, F., Frey, M. M., Guzmán, M. I., Heard, D. E., Helmig, D., Hoffmann, M. R., Honrath, R. E., Huey, L. G., Hutterli, M., Jacobi, H. W., Klán, P., Lefer, B., McConnell, J., Plane, J., Sander, R., Savarino, J., Shepson, P. B., Simpson, W. R., Sodeau, J. R., von Glasow, R., Weller, R., Wolff, E. W., and Zhu, T.: An overview of snow photochemistry: evidence, mechanisms and impacts, Atmos. Chem. Phys., 7, 4329–4373, http://dx.doi.org/10.5194/acp-7-4329-2007doi:10.5194/acp-7-4329-2007, 2007.

Honrath, R. E., Peterson, M. C., Guo, S., Dibb, J. E., Shepson, P. B., and Campbell, B.: Evidence of NO$_\mathrmx$ production within or upon ice particles in the Greenland snowpack, Geophys. Res. Lett., 26, 695–698, 1999.

Honrath, R. E., Peterson, M. C., Lu, Y., Dibb, J. E., Arsenault, M. A., Cullen, N. J., and Steffen, K.: Vertical fluxes of NO$_\mathrmx$, HONO and HNO3 above the snowpack at Summit, Greenland, Atmos. Environ., 36, 2629–2640, 2002.

Jones, A. E., Weller, R., Wolff, E. W., and Jacobi, H.-W.: Speciation and Rate of Photochemical NO and NO2 Production in Antarctic Snow, Geophys. Res. Lett., 27, 345–348, 2000.

Liao, J., Huey, L. G., Tanner, D. J., Brough, N., Brooks, S., Dibb, J. E., Stutz, J., Thomas, J. L., Lefer, B., Haman, C., and Gorham, K.: Observations of hydroxyl and peroxy radicals and the impact of BrO at Summit, Greenland in 2007 and 2008, Atmos. Chem. Phys., 11, 8577–8591, http://dx.doi.org/10.5194/acp-11-8577-2011doi:10.5194/acp-11-8577-2011, 2011.

McElroy, C. T., McLinden, C. A., and McConnell, J. C.: Evidence for bromine monoxide in the free troposphere during the Arctic polar sunrise, Nature, 397, 338–341, 1999.

Ridley, B., Walega, J., Montzka, D., Grahek, F., Atlas, E., Flocke, F., Stroud, V., Deary, J., Gallant, A., Bottenheim, J., Anlauf, K., Worthy, D., Sumner, A. L., Splawn, B., and Shepson, P. B.: Is the Arctic surface layer a source and sink of NO$_\mathrmx$ in winter/spring?, J. Atmos. Chem., 36, 1–22, 2000.

Roscoe, H. K., Brough, N., Jones, A. E., Wittrock, F., Richter, A., Van Roozendael, M., and Hendrick, F.: Resolution of an important discrepancy between remote and in-situ measurements of tropospheric BrO during Antarctic enhancements, Atmos. Meas. Tech. Discuss., 5, 5419–5448, http://dx.doi.org/10.5194/amtd-5-5419-2012doi:10.5194/amtd-5-5419-2012, 2012.

Salawitch, R. J., Canty, T., Kurosu, T., Chance, K., Liang, Q., da Silva, A., Pawson, S., Nielsen, J. E., Rodriguez, J. M., Bhartia, P. K., Liu, X., Huey, L. G., Liao, J., Stickel, R. E., Tanner, D. J., Dibb, J. E., Simpson, W. R., Donohoue, D., Weinheimer, A., Flocke, F., Knapp, D., Montzka, D., Neuman, J. A., Nowak, J. B., Ryerson, T. B., Oltmans, S., Blake, D. R., Atlas, E. L., Kinnison, D. E., Tilmes, S., Pan, L. L., Hendrick, F., Van Roozendael, M., Kreher, K., Johnston, P. V., Gao, R. S., Johnson, B., Bui, T. P., Chen, G., Pierce, R. B., Crawford, J. H., and Jacob, D. J.: A new interpretation of total column BrO during Arctic spring, Geophys. Res. Lett., 37, L21805, http://dx.doi.org/10.1029/2010GL043798doi:10.1029/2010GL043798, 2010.

Scheuer, E., Talbot, R. W., Dibb, J. E., Seid, G. K., DeBell, L., and Lefer, B.: Seasonal distributions of fine aerosol sulfate in the North American Arctic basin during TOPSE, J. Geophys. Res., 108, 8370, doi:10/1029/2001JD001364, 2003.

Sjostedt, S. J., Huey, L. G., Tanner, D. J., Pieschl, J., Chen, G., Dibb, J. E., Lefer, B., Hutterli, M. A., Beyersdorf, A. J., Blake, N. J., Blake, D. R., Sueper, D., Ryerson, T., Burkhardt, J. and Stohl, A.: Observations of hydroxyl and the sum of peroxy radicals at Summit, Greenland during summer 2003, Atmos. Environ., 41, 5122–5137, http://dx.doi.org/10.1016/j.atmosenv.2006.06.065doi:10.1016/j.atmosenv.2006.06.065, 2007.

Stutz, J., Thomas, J. L., Hurlock, S. C., Schneider, M., von Glasow, R., Piot, M., Gorham, K., Burkhart, J. F., Ziemba, L., Dibb, J. E., and Lefer, B. L.: Longpath DOAS observations of surface BrO at Summit, Greenland, Atmos. Chem. Phys., 11, 9899–9910, http://dx.doi.org/10.5194/acp-11-9899-2011doi:10.5194/acp-11-9899-2011, 2011. \hack

Thomas, J. L., Stutz, J., Lefer, B., Huey, L. G., Toyota, K., Dibb, J. E., and von Glasow, R.: Modeling chemistry in and above snow at Summit, Greenland – Part 1: Model description and results, Atmos. Chem. Phys., 11, 4899–4914, http://dx.doi.org/10.5194/acp-11-4899-2011doi:10.5194/acp-11-4899-2011, 2011.

Thomas, J. L., Dibb, J. E., Huey, L. G., Liao, J., Tanner, D., Lefer, B., von Glasow, R., and Stutz, J.: Modeling chemistry in and above snow at Summit, Greenland – Part 2: Impact of snowpack chemistry on the oxidation capacity of the boundary layer, Atmos. Chem. Phys., 12, 6537–6554, http://dx.doi.org/10.5194/acp-12-6537-2012doi:10.5194/acp-12-6537-2012, 2012.

Theys, N., Van Roozendael, M., Hendrick, F., Yang, X., De Smedt, I., Richter, A., Begoin, M., Errera, Q., Johnston, P. V., Kreher, K., and De Mazière, M.: Global observations of tropospheric BrO columns using GOME-2 satellite data, Atmos. Chem. Phys., 11, 1791–1811, http://dx.doi.org/10.5194/acp-11-1791-2011doi:10.5194/acp-11-1791-2011, 2011.

Yang, J., Honrath, R. E., Peterson, M. C., Dibb, J. E., Sumner, A. L., Shepson, P. B., Frey, M., Jacobi, H.-W., Swanson, A., and Blake, N.: Impacts of snowpack photochemistry on levels of OH and peroxy radicals at Summit, Greenland, Atmos. Environ., 36, 2523–2534, 2002.

Ziemba, L. D., Dibb, J. E., Griffin, R. J., Huey, L. G., and Beckman, P.: Observations of particle growth at a remote Arctic site, Atmos. Environ., 44, 1649–1657, http://dx.doi.org/10.1016/j.atmosenv.2010.01.032doi:10.1016/j.atmosenv.2010.01.032, 2010.