Dissolved Zinc in the Southern Ocean measured on water bottle samples during POLARSTERN cruise ANT-XXIV/3

• Main Authors: Croot, Peter L, Baars, Oliver, Streu, Peter
• Format: Dataset
• Language: English
• Published: PANGAEA 2011
• Subjects: ANT-XXIV/3; Bottle number; CTD/Rosette; ultra clean; CTD-UC; Date/Time of event; DEPTH; water; Drake Passage; Element analyser AAS; graphite furnace; Perkin-Elmer 4100 ZL; Elevation of event; Event label; GEOTRACES; Global marine biogeochemical cycles of trace elements and their isotopes; Latitude of event; Longitude of event; Nitrate and Nitrite; Nitrite; Phosphate; Polarstern; Pressure; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; PS71; PS71/103-1; PS71/104-2; PS71/107-3; PS71/113-3; PS71/119-1; PS71/128-1; PS71/131-5; PS71/141-1; PS71/150-2; PS71/167-1; PS71/230-6; PS71/236-3; PS71/241-6; PS71/249-3; Salinity; Scotia Sea; southwest Atlantic; Silicate; South Atlantic Ocean; SPP1158; Temperature; Weddell Sea; Zinc; Antarc*; Antarctic; IPY; Phytoplankton; Sea ice; Southern Ocean; Zooplankton
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.824662; https://doi.org/10.1594/PANGAEA.824662

The distribution of dissolved zinc (Zn) was investigated in the Atlantic sector of the Southern Ocean in the austral autumn of 2008 as part of the IPY GEOTRACES expedition ZERO & DRAKE. Research focused on transects across the major frontal systems along the Zero Meridian and across the Drake Passage. There was a strong gradient in surface zinc concentrations observed across the Antarctic Polar Front along both transects and high zinc levels were found in surface waters throughout the Southern Ocean. Vertical profiles for dissolved Zinc showed the presence of local minima and maxima in the upper 200 m consistent with significant uptake by phytoplankton and release by zooplankton grazing, respectively. Highest deep water zinc concentrations were found in the centre of the Weddell Gyre associated with Central Intermediate Water (CIW), a water mass which is depleted in O2, elevated in CO2 and is regionally a CFC minimum. Our data suggests that the remineralization of sinking particles is a key control on the distribution of Zn in the Southern Ocean. Disappearance ratios of zinc to phosphate (Zn:P) in the upper water column increased southwards along both transects and based on laboratory studies they suggest slower growth rates of phytoplankton due to iron or light limitation. Zinc and silicate were strongly correlated throughout the study region but the disappearance ratio (Zn:Si) was relatively uniform overall except for the region close to the ice edge on the Zero Meridian.