During passage from Stanley (Falklands Islands) to South Georgia, Stanley to Rothera and within the Western Core Box, 14 depth profiles, 70 surface seawater samples and 60 air samples were analysed for trace gas concentrations. In the Western Core Box, 6 CTD casts (3 off-shelf and 3 on-shelf) were carried out. Seawater and air samples were analysed for selected alkyl nitrates and organohalogens using a gas chromatograph - mass selective detector (GC-MSD). Data collected on biological and physical processes occurring within these regions was also used to compare alkyl nitrate and organo-halogen dynamics in these two geographically-close but hydrodynamically different ocean regions.
The 2005-2006 field campaign was to determine alkyl nitrate and organo-halogen concentrations in the upper 100m of the water column at the Rothera Time Series (RaTS) site. Water samples were collected using a Niskin bottle hand winched to depths of 0, 5, 10, 15, 25, 50 and 100m. In total 12 depth profiles were obtained between 4 January and 4 March 2006. All trace gas seawater samples were extracted by purging and the resulting samples were analysed for selected alkyl nitrates and organohalogens using a gas chromatograph - mass selective detector (GC-MSD). The instrument was set up in the Bonner Laboratory at Rothera between November 2005 and April 2006. Sampling was not possible between mid-October and late December 2005 as the sea-ice remaining in the bay was not safe enough to traverse but was too abundant to launch a boat.