The Development of Seawater Standards for Dissolved Nutrients

By Paul Ridout, Ocean Scientific International Ltd. As published in Ocean Challenge, Vol. 9, No. 3 Mass balance equations have shown that the input of the major biologically active nutrients (nitrogen, phosphorous and silicon) to the ocean plays an important role in regulating global oceanic production. Most of these nutrients are terrestrial in origin, finding …

Using IAPSO Standard Seawater

IAPSO Standard Seawater is now only available in bottles. The ampoules were phased out during 2002 and should not still be in use. Thoroughly shake bottle before opening To open bottle simply remove metal crimp cap and take out stopper Use the standard immediately after opening Salinometer standardisation with Standard Seawater should be made regularly …

Preparation and Calibration of IAPSO Seawater Standard

Preparation: Surface seawater is collected from the North Atlantic and then pumped through filters (0.2mm) into a PVC lined tank and thoroughly mixed. Once purified by filtration and UV irradiation, distilled water is added to adjust the salinity, and the water is sealed in pre-washed glass bottles (capacity ca.200cm3). Calibration: The electrical conductivity ratio of …

Linearity Pack

Salinometer calibration for measurement of oceanic samples is traditionally carried out using IAPSO Standard Seawater (salinity = 35). For measurement of samples of higher and lower salinity, OSIL produce standards at salinities of 10, 30 and 38. Salinometer linearity checks provide a useful diagnostic tool in assessing the function of a salinometer and are routinely …

IAPSO Standard Seawater and the Practical Salinity Scale

IAPSO Standard Seawater is the only internationally recognised calibration standard for the measurement of Practical Salinity as approved by all the major oceanographic bodies (ICES, IOC Unesco, SCOR,etc) and is endorsed by the International Association for Physical Sciences of the Ocean (IAPSO). The current definition for Practical Salinity states: a seawater of Practical Salinity 35 …

IAPSO Standard Seawater: Definition of the Uncertainty in the Calibration Procedure, and Stability of Recent Batches

Abstract Standard seawater (SSW) has been employed by oceanographers as a reference material in the determination of salinity for over a century. In all that time, this is the first study to determine the uncertainty of the SSW manufacturing process. SSW is calibrated in reference to carefully prepared solutions of potassium chloride (KCl). All uncertainties in the …

Composition of Ocean Standard Seawater

Composition Atlantic Seawater is prepared from natural open-ocean water collected from the surface waters of the mid-Atlantic. It is treated with ultra-violet light and filtered to 0.2 microns to minimise microbial contamination. However this product is not classified as sterile. The chemical composition of Atlantic Seawater will be similar to published data for open-ocean seawater (see example …

Metrological challenges for measurements of key climatological observables Part 2: oceanic salinity

Salinity is a key variable in the modelling and observation of ocean circulation and ocean-atmosphere fluxes of heat and water. In this paper, we examine the climatological relevance of ocean salinity, noting fundamental deficiencies in the definition of this key observable, and its lack of a secure foundation in the International System of Units, the SI. The metrological history of salinity is reviewed, problems with its current definitions and …