AMT20 (JC053) micro-molar nutrient measurements from CTD bottle samples.

(1) Plymouth Marine Laboratory

This dataset consists of 669 measurements of micromolar nutrient concentrations made on samples collected during the Atlantic Meridional Transect programme cruise 20 (AMT20 JC053) between 14th October and 21st November 2010. The cruise track between UK and Chile passed through both north and south Atlantic gyres. This dataset contributes to the AMT time-series of core oceanographic measurements along an north-south transect of the Atlantic Ocean. Samples were collected on a daily basis at 10 to 12 depths in the upper 300m using a CTD rosette with 24 x 20l OTE (Ocean Test Equipment) bottles. Samples were analysed within 1-2 hours of collection for 'nitrate+nitrite', nitrite, phosphate and silicate using a 5-channel Bran and Luebbe AAIII segmented flow autoanalyser. The analytical chemical methodologies used were according to Brewer and Riley (1965) for nitrate, Grasshoff (1976) for nitrite and Kirkwood (1989) for phosphate and silicate. Silicate data were only included from one station as for many of the samples the silicate values were considered suspect by the originator and not submitted.