Rates of nitrogen fixation in surface waters by stable-isotope mass spectrometry during the AMT programme cruise AMT21 (D371).

This dataset consists of measurements of whole community nitrogen fixation rates and particulate organic nitrogen concentrations from samples collected during the Atlantic Meridional Transect programme cruise 21 (AMT21, D371) between 29th September 2011 and 13th November 2011. The samples were collected at each pre-dawn station from the CTD at four depths per cast (between surface and the deep chlorophyll maximum). Samples were analysed for 14N/15N ratios, PON concentrations and POC concentrations via elemental analyser isotope ratio mass spectrometry. Further details can be found in Snow et al. 2015.