What are two factors that can affect salinity?

Three major factors influence salinity (salt concentration) in Pacific Ocean waters: precipitation, evaporation and winds. Precipitation brings freshwater into the ocean, diluting its salt concentration.

precipitation and evaporation

Explanation:

salinity : salt concentration

Precipitation: this brings freshwater into the ocean which are not salty, so it is diluting its salt concentration.

evaporation: takes all the water and leaves the salt behind