Reactive halogen species can have an important influence on the chemistry of the troposphere. For instance chlorine atoms react faster with most hydrocarbons than OH does and inorganic bromine and iodine can catalytically destroy tropospheric ozone and oxidise mercury. These reactions have been shown to be important in environments as different as the polar troposphere during the springtime ozone depletion events, the boundary layer over salt lakes, and volcanic plumes. There is strong evidence that halogens play a spatially even wider role in the marine boundary layer and free troposphere for ozone destruction, changes in the ratios of OH/HO2 and NO/NO2, destruction of methane, in the oxidation of mercury and in the formation of secondary aerosol. There are indications that both, oceanic sources as well as the chemistry of halogens and volatile organic compounds (VOCs) and oxygenated VOCs (OVOCs) in the tropics are linked with potential implications not only for the photochemistry but also the formation of secondary organic aerosol (SOA). It has been shown how the variability in iodine´s distribution in the ocean can have an impact on iodine production and ozone loss in both the ocean surface and throughout the troposphere. Marine emissions of active halogens have been linked to further potential impacts on oxidants loading in coastal cities. Finally, bromine and iodine are also being proposed as proxies of past sea ice variability.

We invite contributions in the following areas dealing with tropospheric halogens on local, regional, and global scales:

- Model studies: Investigations of the chemical mechanisms leading to release, transformation and removal of reactive halogen species in the troposphere. Studies of consequences of the presence of reactive halogen species in the troposphere.

- Laboratory studies: Determination of gas- and aqueous-phase rate constants, study of complex reaction systems involving halogens, Henry's law and uptake coefficients, UV/VIS spectra, and other properties of reactive halogen species. Biogeochemical controls on iodide formation and loss in the ocean to improve the current parameterizations for iodine emission.

- Field experiments and satellite studies: Measurements of inorganic (X, XO, HOX, XONO2, ..., X = Cl, Br, I) and organic (CH3Br, CHBr3, CH3I, RX, ...) reactive halogen species and their fluxes in the troposphere with in situ and remote sensing techniques.

- Measurements and model studies of the abundance of (reactive) halogen species in volcanic plumes and transformation processes and mechanisms.

- All aspects of tropical tropospheric halogens and links to (O)VOCs: their chemistry, sources and sinks, and their impact on local, regional, and global scales.

Convener: Alfonso Saiz-Lopez | Co-conveners: Nicole Bobrowski, Ulrich Platt, Rolf Sander, Tomás Sherwen
| Mon, 08 Apr, 14:00–15:45
Room 0.60
| Attendance Mon, 08 Apr, 10:45–12:30
Hall X5

Attendance time: Monday, 8 April 2019, 10:45–12:30 | Hall X5

Chairperson: Alfonso Saiz-Lopez
X5.329 |
Rafael Pedro Fernandez, Javier Alejandro Barrera, Fernando Iglesias-Suarez, Carlos Alberto Cuevas, Douglass Kinnison, Jean-Francoise Lamarque, Simone Tilmes, Pamela Wales, Julie Nicely, Ross Salawitch, and Alfonso Saiz-Lopez
X5.332 |
Ilias Bougoudis, Anne-Marlene Blechschmidt, Andreas Richter, Sora Seo, and John P. Burrows
X5.333 |
Moritz Schöne, Holger Sihler, Simon Warnach, Christian Borger, Maximilian Herrmann, Steffen Beirle, Thomas Wagner, and Ulrich Platt
X5.334 |
Shuzhen Chen, Luca Artiglia, Jacinta Edebeli, Xiangrui Kong, Huanyu Yang, Pablo Corral-Arroyo, and Markus Ammann
X5.335 |
| presentation
Kristof Bognar, Xiaoyi Zhao, Kimberly Strong, Xin Yang, Patrick L. Hayes, Samantha Tremblay, Rachel Y-W. Chang, Sara Morris, and Audra McClure-Begley
X5.336 |
Douglas Kinnison, Alfonso Saiz-Lopez, Carlos Cuevas, Rafael Fernandez, Jean-Francois Lamarque, Simone Tilmes, Louisa Emmons, Alma Hodzic, Siyuan Wang, Sue Schauffler, Maria Navarro, and Elliot Atlas
X5.338 |
Xin Yang, Kristof Bognar, Pierre Fogal, Kimberly Strong, kaley Walker, Sara Morris, and Audra McClure-Begley3
X5.339 |
Tomás Sherwen, Martin Wadley, Rosie Chance, Liselotte Tinel, Mat Evans, Lucy Carpenter, David Stevens, Claire Hughes, and Tim Jickells
X5.340 |
Maximilian Herrmann, Ulrich Platt, and Eva Gutheil
X5.341 |
Rosie Chance, Liselotte Tinel, Martin Wadley, Claire Hughes, Tomás Sherwen, Helmke Hepach, Eleanor Barton, Tim Jickells, David Stevens, Anoop Mahajan, Amit Sarkar, and Lucy Carpenter
X5.342 |
Meike Rotermund, Andreas Engel, Jens-Uwe Grooß, Tilman Hüneke, Flora Kluge, Ben Schreiner, Andreas Zahn, and Klaus Pfeilsticker
X5.343 |
Stefan Schmitt, Julian Rüdiger, Dominik Pitton, Nicole Bobrowski, Lukas Tirpitz, Andreas Held, Rolf Sander, Cornelius Zetzsch, and Ulrich Platt
X5.345 |
Erik Hans Hoffmann, Andreas Tilgner, Ralf Wolke, and Hartmut Herrmann