Error calculation of practical salinity determination according to the ctp-data measurements

A.N. Ramazin

Russian Federal Research Institute of Fisheries and Oceanography FSBSI «VNIRO», Russian Federation, Moscow, V. Krasnoselskaya St., 17


DOI: 10.33075/2220-5861-2017-3-7-18

UDK 551.46


     The analysis of errors in the calculation of practical salinity S, arising when use the international algorithm for its calculation using the conductivity C measurement data, the temperature T and the hydrostatic pressure p [1,2,5] is made. The approximations of partial derivatives of these parameters for the equation of total differential of salinity calculation in accordance with the CTp measurements for ranges of salinity variation 2≤S≤42 psu, temperature -2≤Т≤35оС and pressure 0≤р≤10000 dbar are calculated. An analysis is made for the contribution of separate constituents, which are consequence of instrumental errors in CTp measurements to the overall error in the calculation of salinity depending on the values of STp parameters.

Keywords: salinity, error, conductivity, temperature, pressure, partial derivatives, CTpmeasurements.

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  1. Okeanologija: instrumental’nye metody izmerenija osnovnyh parametrov morskoj vody. V.S. Arhipkin, A.Ju. Lazarjuk, D.E. Levashov [i dr.] MAKS Press Moskva, 2009. 336 p.
  2. GSSSD 77-84. Morskaja voda. Shkala prakticheskoj soljonosti 1978 g.
  3. Ramazin A.N., Levashov D.E. Metodicheskie rekomendacii po kalibrovke i metrologicheskomu obespecheniju izmeritelej parametrov vodnoj sredy. Moskow: Izd-vo VNIRO, 2016. 127 p.
  4. IOC, SCOR and IAPSO, 2010: The international thermodynamic equation of seawater 2010: Calculation and use of thermodynamic properties. Intergovernmental Oceanographic Commission, Manuals and Guides. 2010. No. 56, UNESCO (English). 196 p.
  5. Perkin R.G., Levis E.L. The Practical Salinity Scale 1978: Fitting the Date. IEEE. J. of Oceanic Engineering, 1980. OE5. pp. 107–114.
  6. The acquisition, calibration and analysis of CTD data. UNESCO Technical Papers in Marine Science. 54. A report of SCOR Working Group 51.1988.  94 p.