Seawater samples were collected from 15m at the Rothera time series (RaTS) site from February 2005 until March 2007. During summer 2005-2006 samples were analysed using a GC-MS (gas chromatograph mass selective detector) set up in the Bonner laboratory. At all other times samples were stored on solid sorbents at -20C and returned to UEA for analysis. All trace gas seawater samples were extracted by purging and the resulting samples were analysed for selected alkyl nitrates and organohalogens using a 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.
Laboratory data assessing the environmental factors which control photochemical alkyl nitrate production in seawater collected from the Southern Ocean, 2003-2006
Conductivity-Temperature-Depth casts were conducted at Ryder Bay and Marguerite Bay from the James Clark Ross (cruise numbers: JR112/113, JR136/137, JR155 and JR174). The CTD casts at each site were made at a range of depths from the bottom to the surface waters with samples collected for macronutrients, particulate biogenic silica,carbon and nitrogen for later analysis.
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.
Time-series data of bromocarbon compound concentrations - bromoform (CHBr3) and dibromomethane (CH2Br2) concentrations. These were collected at the Rothera Time-Series (RaTS) site, Marguerite Bay during the 2008-2009 field season.
Samples of seawater were collected from the upper watercolumn at the RaTS site and examined to assess bromocarbon production by different microalgal species and how this production varies with changing environmental conditions. The field report (see reference) supplies dates on which the samples were collected and the incubations were started, and the depths incubated.
Two moorings were deployed and recovered using the James Clark Ross (cruise numbers: JR112/113, JR155). One was deployed in Ryder Bay at the Rothera Oceanographic and Biological Time Series (RaTS) oceanographic station midway between Rothera Point and Leonie Islands. The other was deployed in deep water in northern Marguerite Bay. The moorings were used to monitor particle flux, currents, salinity and temperature. Two sediment traps on each mooring were used to measure biogenic flux from surface waters to the seafloor and quantify changes down the water column.
Water samples were collected from Ryder Bay at the Rothera Time-Series (RaTS) site, using a small boat. A biogeochemical profile was performed at the following 5 depths: 0m (surface), 5m, 10m, 15m and 25m, for four RaTS events on: 7 January, 13 January, 19 January and 1 February 2005. Samples were taken for: phytoplankton nitrate, ammonium and urea uptake measurements, using stable isotope incubations and also primary production PvE curves were produced using 14C radioisotope incubations; Dissolved macronutrients (nitrate, silicate, phosphate, and urea); Surface dissolved iron. A scaled-down sampling RaTS event was performed by the Rothera Marine Assistants involving sampling for all above measurements once every 3 weeks at the 5m depth only at the RaTS site.