Dissolved inorganic nutrients (nitrate, phosphate and silicic acid) and chlorophyll a from the combined Nansen Legacy and A-TWAIN Mooring service cruise November 2019
This dataset is a collection of averaged acid-corrected Chlorophyll a (Chla) and phaeopigments, and inorganic nutrient measurements taken as part of the combined Nansen Legacy and A-TWAIN mooring service cruise onboard RV Kronprins Haakon in November 2019, covering the northern Barents Sea and the Atlantic Water inflow region north of Svalbard. Water samples were taken from the CTD rosette at 11-12 depths throughout the water column for determination of Chla, and inorganic nutrients (nitrate plus nitrite (NO3− plus NO2−), phosphate (PO43-) and silicic acid (Si(OH)4 )/silicate (SiO2);concentrations in mmol m−3). For Chla, triplicates of 200 ml were filtered onto GF/F glass microfiber filters (Whatman, England) and frozen until further processing back in the laboratory at UiT The Arctic University of Norway. At UiT, samples were extracted in 5ml of methanol in darkness at 4C for ca. 24 h (Holm-Hansen and Riemann, 1978) and measured with a Turner Triology (Turner, USA). For inorganic nutrients, water samples of 200 mL were collected in acid-washed plastic bottles or in new and rinsed falcon tubes (3x 50 ml) and immediately frozen at -20C until further processing. Following standard methods (Grasshoff et al., 2009) back in the laboratory at UIT The Arctic University of Norway (Tromsø), three replicates were analyzed for each sample. Samples were analysed with a QuAAtro39 AutoAnalyzer (SEAL Analytical), calibrated with reference sea water (Ocean Scientific International Ltd., UK), with detection limits of 0.02 mmol m−3 for nitrate plus nitrite, 0.01 mmol m−3 for nitrite, 0.004 mmol m−3 for phosphate and 0.02 mmol m−3 for silicate (SiO2). The sampling and sample analysis were supported by the Research Council of Norway through the projects The Nansen LEGACY (RCN #276730) and SIOS-InfraNor (RCN #269927), and the Fram Centre project A-TWAIN, project no. 66050.
Holm-Hansen, O., Riemann, B., 1978. Chlorophyll a determination: improvements in methodology. Oikos 30, 438–447. https://doi.org/10.2307/3543338. Grasshoff, K., Kremling, K., Ehrhardt, M., 2009. Methods of Seawater Analysis. John Wiley&Sons, Edition 3, pp. 632
Version history
- Version 1 (2023-11-30): Data publicly available