During the RV Polarstern cruise ARK-XXVII/3 to the Arctic Ocean in summer 2012, when sea ice declined to a record minimum bottom, water and sediment pore water samples were collected with a TV-guided multicorer at stations in the Nansen and Amundsen basin. 50 ml sediment pore water samples were collected from 0-1, 1-5 and 5-10 cm sediment depths from up to 4 parallel sediment cores at each station. Additionally, overlying bottom waters were carefully collected from undisturbed sediment cores. Acidified pore water samples (pH2) were used for analysis of DOC and TDN concentrations. The measurements were performed by hand injection via catalytic oxidation at high temperature on a TOC-V Shimadzu instrument.

This is a contribution to the European Research Council Advanced Investigator Grant 294757 to Antje Boetius.