The Atmosphere

Drivers of Global Change in the Antarctic: Atmospheric Air Sampling

Principal Investigator: Gordon Brailsford
Organisation: NIWA

What we do: The main goals of this programme are to study trace gas species in the Antarctic troposphere and lower stratosphere to better understand the way in which the global changes impact on the Antarctic region. Studies include collections of whole air at Arrival Heights and in the free troposphere between Christchurch and Ross Island; these samples are later analysed for mixing ratio of trace gases such as methane, carbon dioxide, nitrous oxide and carbon monoxide, as well as the isotopic composition of H₂O, CH₄, CO₂, and CO. Our programme also includes the collection of air samples in the lower stratosphere; these samples are then later analysed to better understand the interaction of trace gas species within the Antarctic vortex, and the way in which these interactions change with the development of the ozone hole in spring. Part of this work involves the study of water vapour and its role in the formation of polar stratospheric clouds; these clouds provide sites for the destruction of ozone.

Why we do it: The Antarctic region provides a vast area that is not influenced by man, and therefore the atmosphere is unaffected by local anthropogenic activity. The information obtained from this research can assist in determining the transport of these species from other locations and the way in which they are produced or removed from the atmosphere.

Recent publications:
Allan, W.  Lowe, D.C.  Gomez, A.J.  Struthers, H.  Brailsford, G.W. Interannual variation of 13C in tropospheric methane: implications for possible atomic chlorine sink in the marine boundary layer. Journal of geophysical research 110: D11306, 2005.
 
Franz, P. The isotope composition of water vapour in the upper troposphere/lower stratosphere region: modeling, analysis and sampling. Ph.D. Ruperto-Carola University of Heidelberg. 2005.
 
Manning, M.R.  Lowe, D.C.  Moss, R.C.  Bodeker, G.E.  Allan, W. Short-term variations in the oxidizing power of the atmosphere. Nature 436: 1001-1004, 2005.