Which process causes higher surface salinity in warmer regions?

Which process causes higher surface salinity in warmer regions?

• A. Condensation
• B. Precipitation
• C. Evaporation
• D. Freezing

Answer: (C)

Evaporation is the process at work here. In warmer regions, higher temperatures drive more seawater to vaporize. As water leaves as vapor, the salt is left behind in the remaining surface water, so the dissolved salt concentration increases. Precipitation adds fresh water to the ocean and dilutes salinity, so it lowers surface salinity. Condensation mainly affects the atmosphere and doesn’t concentrate salt in the surface water. Freezing can raise salinity when seawater freezes and salt is expelled from forming ice, but that effect is most pronounced in cold regions, not warm ones. So the higher surface salinity in warmer areas comes from stronger evaporation.

Evaporation is the process at work here. In warmer regions, higher temperatures drive more seawater to vaporize. As water leaves as vapor, the salt is left behind in the remaining surface water, so the dissolved salt concentration increases. Precipitation adds fresh water to the ocean and dilutes salinity, so it lowers surface salinity. Condensation mainly affects the atmosphere and doesn’t concentrate salt in the surface water. Freezing can raise salinity when seawater freezes and salt is expelled from forming ice, but that effect is most pronounced in cold regions, not warm ones. So the higher surface salinity in warmer areas comes from stronger evaporation.