Organic carbon and nitrogen concentrations in surface waters of the North Atlantic along 20°E in July-August 1996 ...

• Main Authors: Körtzinger, Arne, Koeve, Wolfgang, Kähler, Paul, Mintrop, Ludger J
• Format: Dataset
• Language: English
• Published: PANGAEA 2001
• Subjects: Event label; Latitude of event; Longitude of event; Elevation of event; DEPTH, water; Carbon, organic, total; Carbon, organic, total, standard deviation; Nitrogen, organic+inorganic, particulate+dissolved; Nitrogen, standard deviation; Carbon, organic, particulate; Nitrogen, organic, particulate; Nitrogen, inorganic, dissolved; Snorkel with pump; M36/2; Meteor 1986; North Atlantic; Northeast Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.696282; https://doi.pangaea.de/10.1594/PANGAEA.696282

Redfield stoichiometry has proved a robust paradigm for the understanding of biological production and export in the ocean on a long-term and a large-scale basis. However, deviations of carbon and nitrogen uptake ratios from the Redfield ratio have been reported. A comprehensive data set including all carbon and nitrogen pools relevant to biological production in the surface ocean (DIC, DIN, DOC, DON, POC, PON) was used to calculate seasonal new production based on carbon and nitrogen uptake in summer along 20°W in the northeast Atlantic Ocean. The 20°W transect between 30 and 60°N covers different trophic states and seasonal stages of the productive surface layer, including early bloom, bloom, post-bloom and non-bloom situations. The spatial pattern has elements of a seasonal progression. We also calculated exported production, i.e., that part of seasonal new production not accumulated in particulate and dissolved pools, again separately for carbon and nitrogen. The pairs of estimates of 'seasonal new ... : Unfiltered water samples were taken in 10 ml ampoules (sealed immediately after being acidified with phosphoric acid to pH<2, sampling), or 40 ml screw-lid vials, and measured onboard at sampling or next days, or frozen (-20°C) until being acidified and measured in home labs.Carbon measurement was by high-temperature catalytic oxydation in a 10 cm column packed with 5% Pt on aluminum oxide beads at 900°C in a stream of oxygen, and CO2 detection by infrared extinction after the removal of moisture and SO2 by appropriate traps (cold trap, Mg-percarbonate, Na-pyrophosphate, tin, bronze or Sulfix). The apparatus was the dual channel Dimatek 2000 equipped with a Binos 200 detector.Nitrogen was measured by chemoluminescence detection of NO2 in the combustion gases after leaving the Binos detector in one of the two channels of the setup. Most measurements of samples containing high nitrate were discarded, when data were inconsistent. The nature of nitrate interference is not clear. ...