Solute concentrations in sea water
Composition of sea water is virtually constant worldwide
- ~35‰ salinity measured in all major oceans
- The relative proportions of major solutes nearly constant, even where salinity is not 35‰
- Can use chloride concentration, e.g., to determine total salinity; salinity = 1.80665 x chlorinity
Distinguish between
- Conservative constituents, i.e. the major components of the dissolved solids, whose relative concentrations are effectively fixed (i.e. Na+1, Cl-1, or SO4-2)
- Non-conservative constituents, i.e. minor elements whose concentrations are locally altered by biological activity, physical processes, etc. (i.e. NO3-1 or PO4-3)