Publication Date:
2019-09-23
Description:
In order to investigate biogeochemical cycling and dynamics of nutrients, measurement capabilities with sufficient spatial and temporal resolution are required. New ultraviolet-based methods and instrumentation for in situ determination of nitrate provide a powerful tool for these purposes. Here, we present a full dataset obtained by an UV-based process spectrophotometer (ProPS) during a cruise in 2008 in the south-eastern North Sea. Due to highly turbid conditions and mixing water masses, an improved calculation algorithm was performed on the UV absorption data. Nitrate concentrations ranged from 0 to 9 μmol/L on very short timescales, mainly due to tidal effects. Comparison of continuous optical nitrate measurements was performed against conventional wet-chemical analyses of discrete water samples which lead to a standard deviation of 1.7 μmol/L NO3−. High resolution measurements performed at a tidal inlet demonstrated the capability to map nitrate dynamics in turbid coastal environments.
Research highlights:
► We present a new method for in situ determination of nitrate in turbid waters. ► UV spectrophotometer data is coupled with salinity and temperature sampling. ► A full dataset from a coastal inlet in the south-eastern North Sea is presented. ► Comparison against wet-chemical analyses lead to an accuracy of 1.7 μmol/L NO3−. ► High resolution sampling enabled time-space mapping of nitrate dynamics.
Type:
Article
,
PeerReviewed
Format:
text
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