Table of Contents
What happens to salinity when ocean water freezes?
When salt is ejected into the ocean as sea ice forms, the water’s salinity increases. Because salt water is heavier, the density of the water increases and the water sinks.
How does freezing affect the density of ocean water?
Water expands when it freezes making it less dense than the water from which it freezes. In fact, its volume is a little over 9% greater (or density ca. 9% lower) than in the liquid state.
What effect does freezing have on salinity?
Freezing and evaporation both remove water from a water body, and thus increase the salinity.
How does salinity affect the density of seawater?
The density of seawater depends on temperature and salinity. Higher temperatures decrease the density of seawater, while higher salinity increases the density of seawater. Seawater will become stratified with less dense water on the surface and more dense water below it.
What is the relationship between salinity and density?
The more salt there is dissolved in the water, the greater its salinity. When comparing two samples of water with the same volume, the water sample with higher salinity will have greater mass, and it will therefore be more dense.
How does freezing and evaporation affect salinity?
Fresh water, in the form of water vapor, moves from the ocean to the atmosphere through evaporation causing the higher salinity. Toward the poles, fresh water from melting ice decreases the surface salinity once again. Adding salt to water lowers the freezing temperature.
What happens when water salinity increases?
The density of water increases as the salinity increases. The density of seawater (salinity greater than 24.7) increases as temperature decreases at all temperatures above the freezing point. The density of seawater is increased by increasing pressure.
How does salinity affect the freezing point of water?
Incidentally, increasing salinity increases the boiling point and decreases the freezing point. Normal seawater freezes at -2˚ C, 2˚ C colder than pure water. Increasing salinity also lowers the temperature of maximum density.
Why does sea water freeze at a lower temperature than fresh water?
Ocean water freezes at a lower temperature than freshwater. Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit, because of the salt in it. When seawater freezes, however, the ice contains very little salt because only the water part freezes. It can be melted down to use as drinking water.
Two of the most important characteristics of seawater are temperature and salinity – together they control its density, which is the major factor governing the vertical movement of ocean waters. Temperature Distribution in the Ocean The temperature of seawater is fixed at the sea surface by heat exchange with the atmosphere.
What happens when the density of the ocean changes?
What happens when density changes. Dense water sinks below less dense water. This is the principle that drives the deep ocean currents that circulate around the world. A combination of high salinity and low temperature near the surface makes seawater dense enough to sink into the deep ocean and flow along the bottom of the basins.