The conductivity‐density‐salinity‐chlorinity relationships for estuarine waters1

Abstract

The relative conductivity and density of estuarine waters formed by mixing “world” river water with standard seawater have been determined. The results are used to examine the conductivity‐density‐salinity‐chlorinity relationships of estuarine waters of known composition with seawater diluted with pure water (i.e. the new International Equation of State and Practical Salinity Scale). The maximum difference between the true salinity and the value derived from conductivity was 0.047 in dilute solutions; the maximum density difference between the measured and calculated values was 35 × 10−6 g·cm−3. These results are compared with measurements of waters from the St. Lawrence estuary.

Echinoderm Responses to Variation in Salinity

“…The level of accuracy of these devices was limited (1 part in 50 for hydrometers and 1 part in 70-700 for refractometers) relative to titration (1 part in 3000-8000) methods (Pilson, 2012); however, these devices were more convenient and efficient and provided adequate resolution for most ecological and physiological investigations. The practical salinity scale and measures of salinity based on density (%) are the same for coastal and marine environments and within 0.05 units for very dilute estuarine waters (Millero, 1984). S is a conductivity ratio of a sample to standard sea water of known ionic composition and therefore has no units.…”

History of the Equation of State of Seawater

“…(UNESCO, 1985), suggesting that the densities and other thermodynamic properties of most dilute natural waters were similar to seawater at the same absolute salinity. This was demonstrated to be the case for rivers, lakes, and most estuarine waters (Millero, 1975(Millero, , 1984Millero et al, 1976d (Millero, 2006).…”

“…They pointed out that these small changes in density could affect the global circulation of world ocean waters along constant density surfaces. This observation led to a series of papers that examined the limitation of the densityconductivity relationship (Millero et al, ,b,c,d, 1978(Millero et al, , 2008bPoisson et al, 1980bPoisson et al, , 1981Millero, 1984Millero, , 2000. Brewer and Bradshaw, 1975).…”

Algorithm for calculating the mineralization of river waters and salinity of estuarine waters from conductivity data

“…Очевидно, что применение для речных вод общепринятого "океанографического алгоритма" расчета солености [10] из данных электропроводности приведет к большим погрешностям, т. к. макрокомпонентные составы морских и речных вод существенно отличаются. Океанографический алгоритм также может оказаться непригодным для эстуарных вод с низкой соленостью [11,14,16,19].…”