What is the distribution law of seawater salinity?

The distribution law of seawater salinity is decreasing from subtropical waters in the northern and southern hemispheres to high latitudes and low latitudes on both sides.

This is because the subtropical sea area is controlled by the subtropical high zone, with less precipitation, clear weather, strong evaporation and high salinity. The sea area near the equator is controlled by the equatorial low pressure zone, with abundant precipitation and low salinity. Temperate latitude is high, temperature is low, evaporation is weak and salinity is low.

The surface seawater in the world is affected by evaporation, precipitation, freezing, ice melting and land runoff, and the salinity distribution is uneven. Salinity is relatively small near the polar regions, equatorial regions and sea areas affected by land runoff. In the sea area of 20 degrees north and south latitude, the salinity of seawater is relatively high. The salinity of deep seawater has little change, which is mainly controlled by physical processes such as circulation and turbulent mixing.

influencing factor

The salinity of seawater changes with the latitude of the sea area, which is mainly influenced by latitude, rivers, runoff into the sea and ocean currents. In the open sea or ocean, the main factors affecting salinity are precipitation and evaporation. In coastal areas, salinity is mainly affected by river runoff.

From low latitude to high latitude, the salinity of seawater mainly depends on the difference of evaporation and precipitation. Evaporation concentrates seawater, while precipitation dilutes seawater. In the sea area where rivers are injected, the salinity of seawater is generally low.