Effect of Sediment Suspensions on Seawater Salinity Assessments
Journal of Water Resources and Ocean Science
Volume 6, Issue 2, April 2017, Pages: 23-34
Received: Jan. 3, 2017; Accepted: Jan. 20, 2017; Published: Apr. 28, 2017
Views 2131      Downloads 70
Marc Le Menn, Metrology and Chemical Oceanography Department, French Hydrographic and Oceanographic Service (Shom), Brest, France
Laurent Pacaud, Metrology and Chemical Oceanography Department, French Hydrographic and Oceanographic Service (Shom), Brest, France
Article Tools
Follow on us
The absolute salinity of seawater can be assessed by conductivity measurements and the calculation of a practical salinity, or by density measurements. The effect of low concentrations of suspended particulate matter on these measurements has never been documented, but the theories developed to explain and predict the conductivity of sediments show clearly that, under an electrical field, they interact with the ionic composition of seawater. Moreover, it can be easily shown that adding any quantity of particles has an effect on the measured density of a seawater sample. This publication describes a measurement method settled to measure the effect of sediment particles on seawater conductivity and proposes relations for explaining and predicting the observed phenomena. It also describes the effects of particles on density measurements. The results obtained show that the errors on the measured conductivities (and practical salinities) caused by sand in suspensions, are less than 0.001 mS cm-1 (on average) with concentrations encountered in oceans fields, but that these cannot be neglected in some coastal areas. The amplitude of the measurement noise leaded by particles circulation in the conductivity cell exceeds 0.002 in salinity beyond 200 mg l-1. For density measurements, the threshold for keeping the error inferior to the uncertainty of 0.004 kg m-3 usually obtained with vibrating tube densimeters, is much lower, 9 mg l-1, and close to the concentrations encountered in the open ocean.
Seawater, Salinity, Conductivity, Density, Sediment, Formation Factor, Limnology
To cite this article
Marc Le Menn, Laurent Pacaud, Effect of Sediment Suspensions on Seawater Salinity Assessments, Journal of Water Resources and Ocean Science. Vol. 6, No. 2, 2017, pp. 23-34. doi: 10.11648/j.wros.20170602.11
Copyright © 2017 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
IOC, SCOR and IAPSO, 2010, ‘The international thermodynamic equation of seawater – 2010: Calculation and use of thermodynamic properties’, Intergovernmental oceanographic Commission, Manuals Guides n° 56, UNESCO (English), 196 pp.
Millero J. F., Pierrot D., 2002, ‘Speciation of metals in natural seawaters’, Chapter in Chemistry of Marine Water and Sediments, 193-220.
Millero F. J., Feistel R., Wright D. G., MacDougall T. J., 2008a, ‘The composition of standard seawater and the definition of the reference – composition salinity scale’, Deep-Sea Res. I, 55, 10-72.
Pawlowicz R., Wright D. G., and F. J. Millero, 2011, ‘The effects of biogeochemical processes on oceanic conductivity/salinity/density relationships and the characterization of real seawater’, Ocean Sci., 7, 363–387.
Wright D. G., Pawlowicz R., McDougall T. J., Feistel R., and Marion G. M., 2011, ‘Absolute Salinity, “Density Salinity” and the Reference-Composition Salinity Scale: present and future use in the seawater standard TEOS-10’, Ocean Sci., 7, 1–26.
Millero J. F., 1978, ‘The physical chemistry of Baltic Sea waters’, Thalass Jugosl., 14, 1-46.
Millero F. J., Waters, J., Woosley R. J., Huang F., Chanson M., 2008b, ‘The effect of composition on the density of Indian Ocean waters’, Deep-Sea Res. I, 55, 460-470.
Millero J. F., Huang F., 2009, ‘The density of seawater as a function of salinity (5 to 70 gkg-1) and temperature (273.15 to 263.15 K), Ocean Sci., 5, 91-100.
Millero J. F., Huang F., Woosley R. J., Letscher R. T., Hansell D. A., 2011, ‘Effect of dissolved organic carbon and alkalinity on the density of Arctic Ocean waters’, Aquat. Geochem., 17, 311-326.
Woosley R. J., Huang F., Millero F. J., 2014, ‘Estimating absolute salinity (SA) in the world’s oceans using density and composition’, Deep-Sea Res. I, 93, 14-20.
MacDougall T. J., Jackett D. R., Millero J. F., Pawlowicz R., Barker P. M., 2012, ‘A global algorithm for estimating absolute salinity’, Ocean Sci., 8, 1123-1134.
Pawlowicz R., Feistel R., McDougall T. J., Ridout P., Wolf H., 2016, ‘Metrological challenges for measurements of key climatological observables Part 2: oceanic salinity’, Metrologia, 53, R12-R25.
Pawlowicz R., 2015, ‘The absolute salinity of seawater diluted by river water’, Deep-Sea Research I, 101, 71-79.
Held P., Kegler P., Schrottke K., 2014, ‘Influence of suspended particulate matter on salinity measurements’, Continental Shelf Research 85, 1-8, DOI: 10.1016/j.csr.2014.05.014.
Archie G. E., 1942, ‘The electrical resistivity log as an aid in determining some reservoir characteristics’, Petroleum Transactions of the AIME 146, 54-62.
Revil A., Glover P. W. J., 1998, ‘Nature of surface electrical conductivity in natural sands, sandstone, and clays’, Geophys. Res. Let., 25, 5, 691-694.
Revil A., Glover P. W. J., 1997-I, ‘Theory of ionic-surface electrical conduction in porous media’, Physical Review B, 55, 3, 1757-1773.
Waxman M. H., and Smits L. J. M., 1968, ‘Electrical conductivities in oil-bearing shaly sands’, Society of Petroleum Engineer Journal, 107-122
Johnson D. L., Plona T. J., Kojima H., 1986, Proceedings of the second international symposium on the physics and chemistry of porous media, in Physics and Chemistry of Porous Media-II (Ridgefield), edited by Banavar J. R., Koplik J. and Winkler K. W., AIP Conf. Proc. N° 154.
Leroy P., Devau N., Revil A., Bizi M., 2013, ‘Influence of surface conductivity on the apparent zeta potential of amorphous silica nanoparticles’, http://dx.doi.org/10.1016/j.jcis.2013.08.012.
Leroy P., Revil A., Kemna A., Cosenza P., Ghorbani A., 2008, ‘Complex conductivity of water-saturated packs of glass beads’, Journal of Colloid and Interface Science, 321, 103-117.
Revil A., Skold M., 2011, ‘Salinity dependence of spectral induced polarization in sands and sandstones’, Geophys. J. Int., 187, 813-824.
Revil A., Linde N., Cerepi A., Jougnot D., Matthäi S., Finsterle S., 2007, ‘Electro-kinetic coupling in unsaturated porous media’, Journal of Colloid and Interface Science, 313, 1, 315-327.
Revil A., 2013, ‘Effective conductivity and permittivity of unsaturated porous materials in the frequency range 1 mHz – 1 GHz’, Water Resources Research, 49, 306 – 327.
Revil A., Pezard P. A., 1999, ‘Streaming potential in porous media. 1. Theory of the zeta potential’, Journal of geophysical research, 104, B9, 20,021-20,031.
Jackson P. D., Taylor Smith D., Stanford P. N., 1978, ‘Resistivity-porosity-particle shape relationships for marine sands’, Geophysics, 43, 6, 1250-1268.
Comparon L., 2005, Etude expérimentale des propriétés électriques et diélectriques des matériaux argileux consolidés’, Institut de Physique du Globe de Paris and B. R. G. M. theses.
Buck C. S., Landing W. M., Resing J. A., 2010, ‘Particle size and aerosol iron solubility: a high-resolution analysis of Atlantic aerosols’, Marine Chemistry, 120, 1-4, 14-24.
Bressac M., Guieu C., Doxaran D., Bourrin F., Obolensky G., Grisoni J.-M., 2012, ‘A mesocosm experiment coupled with optical measurements to assess the fate and sinking of atmospheric particles in clear oligotrophic waters’, Geo-Mar Letter, 32: 153-164.
Science Publishing Group
1 Rockefeller Plaza,
10th and 11th Floors,
New York, NY 10020
Tel: (001)347-983-5186