GLY150: INTRODUCTION TO OCEANOGRAPHY University of North Carolina Wilmington

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Lecture Outline

Chemical Properties of Ocean Water

I. Salinity

• Seawater
  • 3.5% dissolved salts
  • 96.5% pure water
  • Average seawater salinity is 35 parts per thousand
• Latitudinal variations of surface salinity
• Dissolved salts, six ions
  • Cl-
  • Na+
  • SO42-
  • Mg 2+
  • Ca2+
  • K+
• Constancy of composition
• Measurements of salinity
  • Chlorinity
  • Salinometer
  • Refractometer
• Source of Salts
  • Rivers
  • Volcanoes
• Sinks of Salts
  • Adsorption
  • Biological processes
  • Sea spray
  • Evaporites
  • Infiltration at mid-ocean ridges
• Residence time

II.  Dissolved Gases

• Carbon Dioxide
• Oxygen
  • Factors that control variability with depth
    • photosynthesis
    • respiration
    • decomposition
• Carbon cycle - biological pump

III. Acidity/Alkalinity

• Carbon as a buffer of ocean pH
• Carbon species in oceans
  • carbonic acid
  • bicarbonate
  • carbonate

Some helpful links relevant to this lecture:
NOAA's ocean salinity data
NOAA's ocean oxygen data
States of water

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