DOI 10.1007/s10498-010-9111-2 ORIGINAL PAPER Effect of Dissolved Organic Carbon and Alkalinity on the Density of Arctic Ocean Waters

• Main Authors: Aquat Geochem, Frank J. Millero, Fen Huang, Ryan J. Woosley, Robert T. Letscher, Dennis A. Hansell
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2010
• Subjects: Arctic; Arctic Ocean; Indian; Pacific; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.391.7029; http://yyy.rsmas.miami.edu/groups/biogeochem/Hansell pdfs/80 Hansell.pdf

Abstract At constant temperature, the density of deep waters in the oceans is higher than that of surface waters due to the oxidation of plant material that adds NO3, PO4, and Si(OH)4, and the dissolution of CaCO3(s) that adds Ca 2? and HCO3. These increases in the density have been used to estimate the absolute salinity of seawater that is needed to determine its thermodynamic properties. Density (q), total alkalinity (TA), and dissolved organic carbon (DOC) measurements were taken on waters collected in the eastern Arctic Ocean. The results were examined relative to the properties of North Atlantic Waters. The excess densities (Dq = qMeas- qCalc) in the surface Arctic waters were higher than expected (maximum of 0.008 kg m-3) when compared to Standard Seawater. This excess is due to the higher values of the normalized total alkalinity (NTA = TA * 35/S) (up to *2,650 lmol kg-1) and DOC (up to *130 lmol kg-1) resulting from river water input. New measurements are needed to determine how the DOC in the river waters contributes to the TA of the surface waters. The values of Dq in deep waters are slightly lower (-0.004 ± 0.002 kg m-3) than that in Standard Seawater. The deep waters in the Arctic Ocean, unlike the Atlantic, Pacific, Indian, and Southern Oceans, do not have significant