Radionuclides measured on 27 water bottle profiles during POLARSTERN cruise ANT-XXIV/3 ...

• Main Authors: Rutgers van der Loeff, Michiel M, Cai, Pinghe, Stimac, Ingrid, Bracher, Astrid, Middag, Rob, Klunder, Maarten B, van Heuven, Steven
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2011
• Subjects: CTD/Rosette; ANT-XXIV/3; Polarstern; Global marine biogeochemical cycles of trace elements and their isotopes GEOTRACES; Marine Geochemistry @ AWI AWI_MarGeoChem; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas SPP1158; Antarctic; Arctic; Drake Passage; The Antarctic; Weddell; Weddell Sea; Antarc*; Sea ice
• Online Access: https://dx.doi.org/10.1594/pangaea.745479; https://doi.pangaea.de/10.1594/PANGAEA.745479

As part of the GEOTRACES Polarstern expedition ANT XXIV/3 (ZERO and DRAKE) we have measured the vertical distribution of 234Th on sections through the Antarctic Circumpolar Current along the zero meridian and in Drake Passage and on an EW section through the Weddell Sea. Steady state export fluxes of 234Th from the upper 100m, derived from the depletion of 234Th with respect to its parent 238U, ranged from 621±105 dpm/m**2/d to 1773±90 dpm/m**2/d. This 234Th flux was converted into an export flux of organic carbon ranging from 3.1-13.2 mmolC/m**2/d (2.1-9.0 mmolC/m**2/d) using POC/234Th ratio of bulk (respectively >50 µm) suspended particles at the export depth (100 m). Non-steady state fluxes assuming zero flux under ice cover were up to 23% higher. In addition, particulate and dissolved 234Th were measured underway in high resolution in the surface water with a semi-automated procedure. Particulate 234Th in surface waters is inversely correlated with light transmission and pCO2 and positively with ... : Supplement to: Rutgers van der Loeff, Michiel M; Cai, Pinghe; Stimac, Ingrid; Bracher, Astrid; Middag, Rob; Klunder, Maarten B; van Heuven, Steven (2011): 234Th in surface waters: distribution of particle export flux across the Antarctic Circumpolar Current and in the Weddell Sea during the GEOTRACES expedition ZERO and DRAKE. Deep Sea Research Part II: Topical Studies in Oceanography, 58(25-26), 2749-2766 ...