Atlantic Meridional Transect cruise AMT29 (DY110) in 2019, micro-molar nutrient measurements from CTD bottle samples.

This dataset consists of measurements of micromolar nutrient concentrations made on samples collected during the Atlantic Meridional Transect programme cruise 29 (AMT29 DY110) on the RRS Discovery, between 16th October and 18th November 2019. The cruise track was between Southampton, UK and Punta Arenas, Chile, and passed through both north and south Atlantic gyres. This dataset contributes to the AMT time-series of core oceanographic measurements along a north-south transect of the Atlantic Ocean. Samples were collected twice daily at all sampled CTD's (Total of 55) at selected depths, usually from samples in the upper 500m for the early morning CTD, and down to a maximum depth of 5000m at the solar noon cast. A CTD rosette with 24 x 20L OTE (Ocean Test Equipment) bottles was deployed. Samples were taken and frozen immediately after collection and returned to Plymouth Marine Laboratory, UK, for later analysis. The analyses were for Nitrate+Nitrite, Nitrite, Phosphate, and Silicate, and the analyser was a SEAL Analytical AAIII segmented flow, colorimetric, auto-analyser (Analytical methods: Brewer and Riley (1965) for nitrate, Grasshoff (1976) for nitrite, and Kirkwood (1989) for phosphate and silicate). Established, proven analytical protocols were used and clean sampling and handling techniques were employed according to GO-SHIP protocols (Becker et al, 2020). Certified Nutrient reference materials from KANSO Ltd, Japan (Batch BU), were used during the analysis to ensure good quality control and reliable analytical results.