(Figure 3) Dissolved aluminium concentrations during POLARSTERN Cruise ANT-XXIV/3

• Main Authors: Middag, Rob, van Slooten, C, de Baar, Hein J W, Laan, Patrick
• Format: Dataset
• Language: English
• Published: PANGAEA 2011
• Subjects: Aluminium; standard deviation; ANT-XXIV/3; Bottle number; CTD; CTD/Rosette; ultra clean; CTD-UC; DATE/TIME; DEPTH; water; Elevation of event; Event label; GEOTRACES; Global marine biogeochemical cycles of trace elements and their isotopes; International Polar Year (2007-2008); IPY; Latitude of event; Longitude of event; Oxygen; apparent utilization; Oxygen saturation; Polarstern; PS71; PS71/101-2; PS71/103-1; PS71/104-2; PS71/107-3; PS71/110-1; PS71/113-3; PS71/116-1; PS71/119-1; PS71/122-1; PS71/128-1; PS71/131-5; PS71/135-1; PS71/138-1; PS71/141-1; PS71/144-1; PS71/147-3; PS71/150-2; PS71/161-6; PS71/163-1; PS71/167-1; PS71/175-3; PS71/178-4; Quality flag; South Atlantic Ocean; International Polar Year; North Atlantic Deep Water; North Atlantic; Sea ice; Southern Ocean; Weddell Sea
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.816968; https://doi.org/10.1594/PANGAEA.816968

Dissolved aluminium (Al) occurs in a wide range of concentrations in the world oceans. The concentrations of Al in the Southern Ocean are among the lowest ever observed. An all-titanium CTD sampling system makes it possible to study complete deep ocean sections of Al and other trace elements with the same high vertical resolution of 24 depths as normal for traditional CTD/Rosette sampling. Overall, 470 new data points of Al are reported for 22 full depth stations and 24 surface sampling positions along one transect. This transect consisted of 18 stations on the zero meridian proper from 51°57'S until 69°24'S, and 4 stations somewhat to the northeast towards Cape Town from 42°20'S, 09°E to 50°17'S, 01°27'E. The actual concentrations of Al in the Southern Ocean were lower than previously reported. The concentration of Al in the upper 25 m was relatively elevated with an average concentration of 0.71 nM (n=22; S.D.=0.43 nM), most likely due to atmospheric input by a suggested combination of direct atmospheric (wet and dry) input and indirect atmospheric input via melting sea ice. Below the surface waters there was a distinct Al minimum with an average concentration of 0.33 nM (n=22; S.D.=0.13 nM) at an average depth of 120 m. In the deep southernmost Weddell Basin the concentration of Al increased with depth to ~0.8 nM at 4000 m, and a higher concentration of ~1.5 nM in the ~4500-5200 m deep Weddell Sea Bottom Water. Over the Bouvet triple junction region, where three deep ocean ridges meet, the concentration of Al increased to ~1.4 nM at about 2000 m depth over the ridge crest. In the deep basin north of the Bouvet region the concentration of Al increased to higher deep values of 4-6 nM due to influence of North Atlantic Deep Water. In general the intermediate and deep distribution of Al results from the mixing of water masses with different origins, the formation of deep water and additional input from sedimentary sources at sea floor elevations. No significant correlation between Al and silicate (Si) was ...