Dissolved iron, total dissolvable iron, and dissolved manganese concentrations from CTD casts at stations between 54S, 89W and 60S, 89W on CUSTARD cruise DY111.

This dataset contains concentrations of dissolved iron (< 0.2 µm), total dissolvable iron (unfiltered), and dissolved (< 0.2 µm) manganese, together with their uncertainties. Data were collected along longitude 89W at 7 different repeat stations: OOI at 54S, TN at 57S, TS at 60S, Tran_1 at 55S, Tran_2 at 56S, Tran_3 at 58S, and Tran_4 at 59S. Data collection took place on board RRS Discovery cruise DY111 between the 6th of December 2019 and the 3rd of January 2020. Data were obtained from 20 titanium CTD casts. Samples were drawn from 10 L OTE bottles into acid clean LDPE bottles, acidified to 0.024 M HCl, and stored for over 9 months. Iron was analysed by flow injection with chemiluminescence detection, and manganese by off-line preconcentration with subsequent high-resolution inductively coupled plasma mass spectrometry (ICP-MS). These data were collected to examine seasonal changes in biogeochemistry in the Southern Ocean across the spring bloom as part of the Carbon Uptake and Seasonal Traits in Antarctic Remineralisation Depth (CUSTARD) project (NERC grant NE/P021247/1).