| Title of dataset | Macronutrient data collected by RRS James Clark Ross cruise 161 around the Scotia Sea and South Georgia (Southern Ocean), Oct-Dec 2006 |
| Narrative summary of dataset | The dataset comprises macronutrient (nitrate, phosphate, silicate, ammonia/ammonium) data collected on RRS James Clark Ross cruise 161 around the Scotia Sea and South Georgia in the Southern Ocean. The data were collected using CTD rosette water bottles and the ship's non-toxic seawater supply with an intake depth about 6 - 7 m between 24 October and 03 December 2006 as part of an integrated ecosystem analysis. They form part of a more extensive dataset collected over 30 years, between 1980 and 2009, by the British Antarctic Survey. |
| Summary of processing methodology | Samples for vertical profiles were collected from water bottles attached to a CTD rosette while samples for horizontal transects were collected from the ship's non-toxic seawater supply with an intake depth about 6 - 7 m. Chemical analyses were undertaken using a custom-built Segmented-Flow Analyser initially based on Chemlab colorimeters and Ismatec proportioning pumps until 1993 when Technicon colorimeters were adopted. Initially, data were logged to paper chart and processed manually but in the mid-1980s, data extraction was automated and processing was managed with a digitising tablet and associated PC. In 1993 as part of a comprehensive re-build, data were logged to a PC. Data acquisition and subsequent processing was achieved with custom-built software (BAS in-house and Cambridge Beacon Ltd) and this was updated further in the mid-1990s when National Instrument data acquisition programmes were used to collect data, and calibration along with data organisation were switched to commercially available spreadsheets. Data collected during transecting were logged along with a time-stamp acquired from the central ship's clock to allow synchronisation with concurrent measurements such as temperature and salinity from the ship's Oceanlogger system.
For further details see: Whitehouse et al (2023), included in the data package, and referenced in the Documentation section. |
| Supporting documentation | Whitehouse, M. J., Hendry, K. R., Tarling, G. A., Thorpe, S. E., and ten Hoopen, P.: A database of marine macronutrient, temperature and salinity measurements made around the highly productive island of South Georgia, the Scotia Sea and the Antarctic Peninsula between 1980 and 2009, Earth Syst. Sci. Data, 15, 211-224, https://doi.org/10.5194/essd-15-211-2023, 2023. Shreeve, R.: RRS James Clark Ross Cruise JR161: A study of pelagic marine food web interactions and condition factors of zooplankton across the Scotia Sea, BODC Cruise Inventory, 324 pp, https://www.bodc.ac.uk/resources/inventories/cruise_inventory/reports/jr161.pdf, 2006. |
| Cruise | 43_8262 |
| Start date | 2006-10-24 |
| End date | 2006-12-03 |