Ligands Phantastic Version 5

DFe and DFe-binding organic ligands were measured using Competing Ligand Exchange Cathodic Stripping Voltammetry (CLE-CSV) with TAC as competing ligand in the vicinity of the Ross Sea during a cruise between 20 December 2013 and 5 January 2014. DFe-binding organic ligand concentrations were highest in the Ross Sea Polynya and the Antarctic Circumpolar Current west of the Ross Sea, in association with seasonal phytoplankton blooms. Phytoplankton sources and sinks of DFe-binding organic ligands are probably related to seasonal differences in the stage of the bloom. In 39% of the samples, two DFe-binding organic ligand groups were distinguished based on the difference in binding strength. The distinction was especially clear in the RSP and in the West ACC (54 and 77% of the samples, respectively) where blooms occurred and much less in the East ACC and ice covered eastern part of the Ross Sea (15 and 10% of the samples, respectively).