Computation of nitrate concentrations in coastal waters using an in situ ultraviolet spectrophotometer: Behavior of different computation methods in a case study a steep salinity gradient in the southern North Sea

Adornato, L., Cardenas-Valencia, A., Kaltenbacher, E., Byrne, R.H., Daly, K., Larkin, K., Hartman, S., Mowlem, M., Prien, R.D., Garcon, V., 2010. In situ nutrient sensors for ocean observing systems. European Space Agency, December, pp. 1–10. URL: http://www.oceanobs09.net/proceedings/cwp/cwp01/index.php. Carroll, M., Chigounis, D., Cook, J., Gilbert, S., Johengen, T., Koles, T., Mckissack, T., Wells, D., Mcintyre, M., Pinchuk, A., Purcell, H., Robertson, C., Schar, D., Smith, G.J., Tamburri, M., 2007. Performance demonstration statement: Satlantic ISUS V3 Nitrate Sensor. Tech. Rep., Alliance for Coastal Technologies, Solomons. Dore, 1996, Freezing as a method of sample preservation for the analysis of dissolved inorganic nutrients in seawater, Mar. Chem., 53, 173, 10.1016/0304-4203(96)00004-7 1999 Johnson, 2002, In situ ultraviolet spectrophotometry for high resolution and long-term monitoring of nitrate, bromide and bisulfide in the ocean, Deep-Sea Res. I, 49, 1291, 10.1016/S0967-0637(02)00020-1 Johnson, 2013, Long-term nitrate measurements in the ocean using the in situ ultraviolet spectrophotometer: sensor integration into the APEX profiling float, J. Atmos. Ocean. Technol., 10.1175/JTECH-D-12-00221.1 Jortner, 1964, On the photochemistry of aqueous solutions of chloride, bromide, and iodide ions, J. Phys. Chem., 68, 247, 10.1021/j100784a005 Lewis, 2010, Interference with spectrophotometric analysis of nucleic acids and proteins by leaching of chemicals from plastic tubes, BioTechniques, 48, 297, 10.2144/000113387 MacDonald, 1982, The effect of storage by freezing on dissolved inorganic phosphate, nitrate and reactive silicate for samples from coastal and estuarine waters, Water Res., 16, 95, 10.1016/0043-1354(82)90058-6 Petersen, W., Colijn, F., Hydes, D., Schroeder, F., 2007. FerryBox: from on-line oceanographic observations to environmental information. EU Project FerryBox 2002–2005. Tech. Rep. URL: http://eprints.soton.ac.uk/50279/http://en.scientificcommons.org/26523787. Sakamoto, 2009, Improved algorithm for the computation of nitrate concentrations in seawater using an in situ ultraviolet spectrophotometer, Limnol. Oceanogr. Methods, 7, 132, 10.4319/lom.2009.7.132 Salim, 2011, Stray light correction for diode-array-based spectrometers using a monochromator, Appl. Opt., 50, 5130, 10.1364/AO.50.005130 Stedmon, 2010, Tracing water mass mixing in the Baltic–North Sea transition zone using the optical properties of coloured dissolved organic matter, Estuarine Coastal Shelf Sci., 87, 156, 10.1016/j.ecss.2009.12.022 Zielinski, O., Fiedler, B., Heuermann, R., Kortzinger, A., Kopiske, E., Meinecke, G., Munderloh, K., 2007. A new nitrate continuous observation sensor for autonomous sub-surface applications: technical design and first results. In: OCEANS 2007—Europe, June, pp. 1–4. URL: http://ieeexplore.ieee.org/lpdocs/epic03/wrapper.htm?arnumber=4302300. Zielinski, 2011, Computation of nitrate concentrations in turbid coastal waters using an in situ ultraviolet spectrophotometer, J. Sea Res., 65, 456, 10.1016/j.seares.2011.04.002