The universal ratio of boron to chlorinity for the North Pacific and North Atlantic oceans

Kitack Lee, Tae Wook Kim, Robert H. Byrne, Frank J. Millero, Richard A. Feely, Yong Ming Liu

Research output: Contribution to journalArticlepeer-review

383 Citations (Scopus)


We report seawater boron concentration (mg kg-1) and chlorinity (‰) values measured in seawater samples (n = 139) collected at various depths in the North Pacific and North Atlantic oceans and the East/Japan Sea (located in the western temperate North Pacific). Our results indicate that variations in seawater boron concentration are strongly coupled to variations in chlorinity (and salinity), yielding a mean boron to chlorinity ratio of 0.2414 ± 0.0009 mg kg-1-1 (boron to salinity ratio = 0.1336 ± 0.0005 mg kg-1-1). This ratio was surprisingly universal throughout the water column in the three marine basins and across widely different ocean surface regimes, but differs from the generally accepted ratio of 0.232 ± 0.005 mg kg-1-1 determined by Uppström (1974), which was based on only 20 measurements at four sites in the tropical Pacific Ocean. In converting total alkalinity to carbonate alkalinity (and vice versa) for thermodynamic calculations, the difference between these two ratios leads to a difference of 5 μmol kg-1 in estimates for ocean surface waters, where the contribution of borate to total alkalinity is typically greatest. We suggest the use of the new boron to chlorinity ratio for predicting seawater boron concentrations using chlorinity (or salinity) data.

Original languageEnglish
Pages (from-to)1801-1811
Number of pages11
JournalGeochimica et Cosmochimica Acta
Issue number6
Publication statusPublished - 2010 Mar 15
Externally publishedYes

Bibliographical note

Funding Information:
We thank Eric Grabowski (chief scientist) and Fernando Santiago of the University of Hawaii for collecting seawater samples from the Hawaiian Ocean Time Series station. Special thanks are extended to Nick Bates and Melchor González Dávila for collecting seawater samples from the Bermuda Atlantic Time Series Study and the European Station for Time-series in the Ocean off the Canary Islands, respectively. We also thank Rik Wanninkhof of the Atlantic Oceanographic and Meteorological Laboratory for providing us with valuable comments on the manuscript. This work was financially supported by the National Research Laboratory (NRL) of the Korean Science and Engineering Foundation. Partial support was provided by the Oceanographic Section of the National Science Foundation and the National Oceanic and Atmospheric Administration .

Copyright 2011 Elsevier B.V., All rights reserved.

ASJC Scopus subject areas

  • Geochemistry and Petrology


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