World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

An Algorithm for Estimating Absolute Salinity in the Global Ocean : Volume 6, Issue 1 (09/02/2009)

By McDougall, T. J.

Click here to view

Book Id: WPLBN0004021075
Format Type: PDF Article :
File Size: Pages 28
Reproduction Date: 2015

Title: An Algorithm for Estimating Absolute Salinity in the Global Ocean : Volume 6, Issue 1 (09/02/2009)  
Author: McDougall, T. J.
Volume: Vol. 6, Issue 1
Language: English
Subject: Science, Ocean, Science
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2009
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Jackett, D. R., Millero, F. J., & Mcdougall, T. J. (2009). An Algorithm for Estimating Absolute Salinity in the Global Ocean : Volume 6, Issue 1 (09/02/2009). Retrieved from http://worldlibrary.net/


Description
Description: Centre for Australian Weather and Climate Research: A partnership between CSIRO and the Bureau of Meteorology, Hobart, TAS, Australia. To date, density and other thermodynamic properties of seawater have been calculated from Practical Salinity, S P. It is more accurate however to use Absolute Salinity, S A (the mass fraction of dissolved material in seawater). Absolute Salinity S A can be expressed in terms of Practical Salinity S P as

S A=(35.165 04 g kg-1/35)S PS A(φ, Λ, p)

where Δ S A is the Absolute Salinity Anomaly as a function of longitude φ, latitude λ and pressure. When a seawater sample has standard composition (i.e. the ratios of the constituents of sea salt are the same as those of surface water of the North Atlantic), the Absolute Salinity Anomaly is zero. When seawater is not of standard composition, the Absolute Salinity Anomaly needs to be estimated; this anomaly is as large as 0.025 g kg−1 in the northernmost North Pacific. Here we provide an algorithm for estimating Absolute Salinity Anomaly for any location (φ, Λ, p) in the world ocean.

To develop this algorithm we use the Absolute Salinity Anomaly that is found by comparing the density calculated from Practical Salinity to the density measured in the laboratory. These estimates of Absolute Salinity Anomaly however are limited to the number of available observations (namely 811). To expand our data set we take advantage of approximate relationships between Absolute Salinity Anomaly and silicate concentrations (which are available globally). We approximate the laboratory-determined values of Δ S A of the 811 seawater samples as a series of simple functions of the silicate concentration of the seawater sample and latitude; one function for each ocean basin. We use these basin-specific correlations and a digital atlas of silicate in the world ocean to deduce the Absolute Salinity Anomaly globally and this is stored as an atlas, Δ S A (φ, Λ, p). This atlas can be interpolated to the latitude, longitude and pressure of a seawater sample to estimate its Absolute Salinity Anomaly.

For the 811 samples studied, ignoring the Absolute Salinity Anomaly results in a standard error in S A of 0.0107 g kg-1. Using our algorithm for Δ S A reduces the error to 0.0048 g kg−1, reducing the mean square error by a factor of five. The number of sea water samples used to develop the correlation relationship is limited, and we hope that the algorithm and error can be improved as further data becomes available.


Summary
An algorithm for estimating Absolute Salinity in the global ocean

Excerpt
Brewer, P. G. and Bradshaw, A.: The effect of non-ideal composition of seawater on salinity and density, J. Mar. Res., 33, 157–175, 1975.; Feistel, R.: A Gibbs function for seawater thermodynamics for −6 to 80 \textdegree C and salinity up to 120 g kg−1, Deep-Sea Res. I, 55, 1639–1671, 2008.; Feistel, R., Wright, D. G., Miyagawa, K., Harvey, A. H., Hruby, J., Jackett, D. R., McDougall, T. J., and Wagner, W.: Mutually consistent thermodynamic potentials for fluid water, ice and seawater: a new standard for oceanography, Ocean Sci., 4, 275–291, doi:10.5194/os-4-275-2008, 2008.; Feistel, R., Weinreben, S., Wolf, H., Seitz, S., Spitzer, P., Adel, B., Nausch, G., Schneider, B., and Wright, D. G.: Density and Absolute Salinity of the Baltic Sea 2006–2009, Ocean Sci., 6, 3–24, doi:10.5194/os-6-3-2010, 2010.; Gouretski, V. V. and Koltermann, K. P.: WOCE global hydrographic climatology. Berichte des Bundesamtes für Seeschifffahrt und Hydrographie Tech. Rep. 35/2004, 49 pp., this atlas is available at: www.bsh.de/aktdat/mk/AIMS, 2004.; IAPWS: Release on the IAPWS Formulation 2008 for the Thermodynamic Properties of Seawater. The International Association for the Properties of Water and Steam, available at: www.iapws.org, Berlin, Germany, September 2008.; IOC, SCOR, and IAPSO: The international thermodynamic equation of seawater – 2010: Calculation and use of thermodynamic properties. Intergovernmental Oceanographic Commission, Manuals and Guides No. 56, UNESCO (English), available at: www.TEOS-10.org, 196 pp., 2010.; Knudsen, M.: Hydrographische Tabellen, G. E. C. Gad, Copenhagen; L. Friedrichsen & Co., Hamburg; Williams & Norgate, London; and Buchdruckerei Bianco Luno, 63pp., 1901.; Kremling, K.: New Method for measuring density of seawater, Nature, 229, 109–110, 1971.; McDougall, T. J.: The International Thermodynamic Equation of Seawater – 2010; Introductory Lecture Slides, available at: www.TEOS-10.org, 2012.; McDougall, T. J. and Barker, P. M.: Getting started with TEOS-10 and the Gibbs Seawater (GSW) Oceanographic Toolbox, www.TEOS-10.org, SCOR/IAPSO WG127, ISBN 978-0-646-55621-5, 28 pp., 2011.; Millero, F. J.: Effect of changes in the composition of seawater on the density-salinity relationship, Deep-Sea Res. I, 47, 1583–1590, 2000.; Millero, F. J.: History of the equation of state of seawater, Oceanography, 23, 18–33, 2010.; Millero, F. J. and Kremling, K.: The densities of Baltic Sea waters, Deep-Sea Res., 23, 1129–1138, 1976.; Millero, F. J., Gonzalez, A., Brewer, P. G., Bradshaw, A.: The density of North Atlantic and North Pacific deep waters, Earth Planet. Sci. Lett., 32, 468–472, 1976a.; Millero, F. J., Chetirkin, P. V., and Culkin, F.: The relative conductivity and density of standard seawaters, Deep-Sea Res., 24, 315–321, 1976b.; Millero, F. J., Forsht, D., Means, D., Giekes, J., and Kenyon, K.: The density of North Pacific Ocean waters, J. Geophys. Res., 83, 2359–2364, 1978.; Millero, F. J., Feistel, R., Wright, D. G., and McDougall, T. J.: The composition of Standard Seawater and the definition of the Reference-Composition Salinity Scale, Deep-Sea Res. I, 55, 50–72, 2008a.; Millero, F. J., Waters, J., Woosley, R., Huang, F., and Chanson, M.: The effect of composition of the density of Indian Ocean waters, Deep-Sea Res. I, 55, 960–470, 2008b.; Millero, F. J., Mirzaliyev, A., Safarov, J., Huang, F., Chanson, M., Shahverdiyev, A., and Hassel, E.: The equation of state for Caspian Sea waters, Aqua. Geochem., 14, 289–299, 2008c.; Millero, F. J., Huang, F., Williams, N., Waters, J., and R. Woosley: The effect of composition on the density of South Pacific Ocean water

 

Click To View

Additional Books


  • Development of a New Expendable Probe fo... (by )
  • Corrigendum to a New Method for Forming ... (by )
  • Support to Oil Spill Emergencies in the ... (by )
  • On the Shelf Resonances of the English C... (by )
  • Eddy Characteristics in the South Indian... (by )
  • Consistency of the Current Global Ocean ... (by )
  • A Computational Method for Determining X... (by )
  • Influence of the Kuroshio on the Water P... (by )
  • Observing the Mediterranean Sea from Spa... (by )
  • Impact of the Sea Surface Temperature Fo... (by )
  • A Geographical and Seasonal Comparison o... (by )
  • Modal Composition of the Central Water i... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.