Dimethylsulfide and its precursors and derivatives constitute a major sulfate aerosol source. This dataset incorporates the potential for increased UV radiation effects due to stratospheric ozone depletion over spring and summer in Antarctica, using large-scale incubation systems and 13-14 day incubation periods. Surface seawater (200 micron filtered) from the Davis coastal embayment was incubated during four experiments over the 2002-03 Antarctic Summer. The data incorporates seawater measurements of DMS, DMSP and DMSO over a temporal progression during each incubation experiment. Six polyethylene tanks of varying PAR and UV irradiances were incubated. Water was collected stored and analysed by gas chromatography according to a specific sampling protocol, employed by all investigators associated with the project. The data are organised according to analysis day, with each days calibration data displayed at the top of each sheet. The sample code is followed by GC run number and then the raw count data from the GC. This is calculated to nanomoles DMS, DMSP or DMSO. Sample Codes: Codes for temporal data follow format X.XXXX 1st X gives experiment number, 1 to 4. 2nd X gives sampling day, 0, 0.5, 1, 2, 4, 7, 14 (will result in digit code for day no. less than 10 3rd X gives tank number relating to irradiance level(one to six) 4th and 5th X is replicate number, (01, 02, 03, DMS), (04, 05,06, DMSP total), (07, 08, 09, DMSP dissolved), (10, 11, 12, DMSO total). The fields in this dataset are: Sample Code Run Number from the GC Counts - GC generated raw data Log Counts - logarithmic conversion of the count data Log -c - logarithmic conversion minus the y-intercept determined by calibration of the GC. (log -c)/m - log -c divided by m, determined by calibration of the GC. ngS anti log - nanograms of Sulfur NaOH - NaOH adjustment ngS/L - adjustment per litre nM-DMSP/L - nanoMol's DMSP per litre nm-DMS/L - nanoMol's DMS per litre September 2013 Update: DMSO was analysed in these experiments according to an adaptation of the sodium borohydride (NaBH4) reduction method of Andreae (1980). The method has since been superseded and the data here probably displays inaccuracies as a result of the analytical method used. This DMSO data should be treated with caution.

Peter Sedwick collected water column samples (6 depths, less than 350m) and measured dissolved iron in these samples, using specialised trace-metal clean techniques, at 9 stations along the SR3 transect between 47 deg S and 66 deg S. These are the first such data for this oceanographic sector during spring. The dissolved iron levels were generally very low (less than 0.2 nM nM) in the upper water column, particularly south of the Subantarctic Front, and surprisingly there was no evidence of significant iron inputs from melting sea ice in our study region. Ongoing work quantified various size fractions of dissolved iron as well as total acid soluble iron. In addition, Jack DiTullio collected water samples for measurements of five biogenic sulfur pools at most shallow water CTD casts. The sulfur pools measured include: dimethylsulfide (DMS), particulate and dissolved dimethylsulfoniopropionate (DMSP) and particulate and dissolved pools of dimethylsulfoxide (DMSO). Taken from the referenced paper: A shipboard-deployable, flow-injection (FI) based instrument for monitoring iron(II) in surface marine waters is described. It incorporates a miniature, low-power photoncounting head for measuring the light emitted from the iron-(II)-catalyzed chemiluminescence (CL) luminol reaction. System control, signal acquisition, and data processing are performed in a graphical programming environment. The limit of detection for iron(II) is in the range 8-12 pmol L-1(based on 3s of the blank), and the precision over the range 8-1000 pmol L-1 varies between 0.9 and 7.6% (n )4). Results from a day-night deployment during a north to-south transect of the Atlantic Ocean and a daytime transect in the Sub-Antarctic Front are presented together with ancillary temperature, salinity, and irradiance data. The generic nature of the components used to assemble the instrument make the technology readily transferable to other laboratories and the modular construction makes it easy to adapt the system for use with other CL chemistries.

From 1991 to 2000 14 voyages have been completed in the Southern Ocean. Measurements of DMS (Dimethylsulfide) and DMSP (Dimethylsulfoniopropionate) have been carried out on surface and subsurface waters together with physical and biological measurements, with a view to understanding the main processes that affect DMS in the Southern Ocean. The first flux measurements have been carried out for DMS (see Curran and Jones 2000) in the last 3 years a concerted study has been carried out in the seasonal ice zone this study aims to identify the major phytoplankton assemblages responsible for DMS and DMSP production in the sea ice zone. It is thought that the sea ice zone also contributes to DMS in the atmosphere. This is being quantified. The fields in this dataset are: Site Date Time (local) Latitude Longitude Snow Cover (metres) Core Length (metres) DMSPt (nano Mols) Chlorophyl a (micrograms per litre) Sea Ice depth (metres) Pigments Fucoxanthin (micrograms per litre) Peridinin (micrograms per litre) 19' hexanoyloxyfucoxanthin (micrograms per litre) Salinity (ppt) Nitrate (micro Mols) Nitrite (micro Mols) Silicate (micro Mols) Phosphate (micro Mols)