Atmospheric chemistry measurements of bromine explosion/mercury deposition during the Polar Spring SIPEX II, 2012 Campaign
Robyn Schofield

Authors

Robyn Schofield¹, Ruhi Humphries², Caitlin Gionfriddo¹, Karin Kreher³*, Paul Johnston³, Neil Harris⁴, Andrew Robinson⁴, Michael Tate⁵, David Krabbenhoft⁵, John W. Moreau¹, Suzie Molloy⁶, Ian Galbally⁶, Melita Keywood⁶, Stephen Wilson², Simon Alexander⁷, Andrew Klekociuk⁷, Andrew Bowie^8,9, Delphine Lannuzel^8,9 and Klaus Meiners⁸

1. School of Earth Sciences, University of Melbourne, VIC 3010, Australia
2. Centre for Atmospheric Chemistry, University of Wollongong, NSW 2522, Australia
3. National Institute of Water and Atmospheric Research, Lauder, New Zealand
4. Centre for Atmospheric Science, Department of Chemistry, Cambridge CB2 1EW, England
5. US Geological Survey, Middleton, WI53562, United States
6. Centre for Australian Weather and Climate Research, CSIRO Marine and Atmospheric Research, VIC 3195, Australia
7. Australian Antarctic Division, TAS 7050, Australia
8. Antarctic Climate and Ecosystems, Cooperative Research Centre, Hobart, TAS 7001, Australia
9. Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7001, Australia

*Now at Bodeker Scientific, Alexandra, New Zealand

Abstract

Bromine explosion events that occur over first year sea ice in the polar spring cause mercury deposition and dramatically alter the oxidative capacity of the polar boundary layer. Atmospheric chemical measurements made during the Sea Ice Physics and Ecosystems eXperiment (SIPEX II) in the polar spring of 2012 are presented here. Vertical BrO, NO₂, HCHO profile concentrations were made with a UV-Vis Multi-AXis Differential Optical Absorption Spectrometer (MAX-DOAS). Halocarbon (i.e. CH2CH2, CHBr3) observations were made using a GC-ECD µ-Dirac and gaseous elemental mercury (GEM) observations made using a Tekran instrument along with in-situ ozone and aerosol new particle observations. In addition, snow-sea-ice and ocean samples were made at several ‘ice stations’ between 62- 65°S and 115-121°E to analyze for total mercury and methylmercury. Several mercury and ozone depletion events were observed. This suite of observations provides the most complete suite of observations to date to improve our understanding of the implications of BrO explosion events in the Antarctic under changing future sea-ice conditions.