Salinity
E < P
E > P
q  Salinity is the mass of
dissolved salts in a
kilogram of seawater.
q  Unit: ‰ (part per
thousand; per mil).
q  The average salinity of
the world ocean is 34.7‰.
q  Four major factors that
affect salinity: evaporation,
precipitation,  inflow of
river water, and sea-ice
formation and melting.