Much of the open ocean has a salinity between 34ppt and 36ppt. Salinity is controlled by a balance between water removed by evaporation and freshwater added by rivers and rain. The Mediterranean Sea in Europe has very high salinity — 38 ppt or more. Evaporation of ocean water and formation of sea ice both increase the salinity of the ocean. To understand how salty the sea is, start with mL of water 1 cup. This is just short of 2 teaspoons, so it would be close enough to add 2 level teaspoons of salt to the cup of water.
Seawater is toxic to humans because your body is unable to get rid of the salt that comes from seawater. Salinity affects production in crops, pastures and trees by interfering with nitrogen uptake, reducing growth and stopping plant reproduction.
Some ions particularly chloride are toxic to plants and as the concentration of these ions increases, the plant is poisoned and dies. Rivers and lakes can have a wide range of salinities, from less than 0. This is mainly due to the huge amount of freshwater added from hundreds of rivers. Even slightly denser seawater sinks below less dense water. However, the effect is greater if the salty water gets cold, as temperature has a greater effect on density than salinity does.
A combination of high salinity and low temperature makes seawater so dense that it sinks to the bottom of the ocean and flows across ocean basins as deep, slow currents. Add to collection. Go to full glossary Add 0 items to collection. Download 0 items. Twitter Pinterest Facebook Instagram. Land and ice emit very bright microwave emissions that swamp the signal read by the satellite.
Another factor that affects salinity readings is intense rainfall. Heavy rain can affect salinity readings by attenuating the microwave signal Aquarius reads off the ocean surface as it travels through the soaked atmosphere. Rainfall can also create roughness and shallow pools of fresh water on the ocean surface. An ultimate goal is combining the Aquarius measurements to those of its European counterpart, the Soil Moisture and Ocean Salinity satellite SMOS to produce more accurate and finer maps of ocean salinity.
In addition, the Aquarius team, in collaboration with researchers at the U. Learn More About This Image. Salinity Although everyone knows that seawater is salty, few know that even small variations in ocean surface salinity i. This movie shows salinity patterns as measured by Aquarius from December through December Red colors represent areas of high salinity, while blue shades represent areas of low salinity. It is important to understand salinity, the amount of dissolved salts in water, because it will lead us to better understanding of the water cycle and can lead to improved climate models.
High concentrations over 37 practical salinity units are usually in the center of the ocean basins away from the mouths of rivers, which input fresh water. High concentrations are also in sub-tropical regions due to high rates of evaporation clear skies, little rain, and prevailing winds and in landlocked seas in arid regions. At high latitudes, salinity is low.
This can be attributed to lower evaporation rates and the melting of ice that dilutes seawater. To sum up, salinity is low where precipitation is greater than evaporation, mainly in coastal or equatorial regions. This expansion, and corresponding decrease in density, is the reason ice floats. Titanic Bergs. The amount of salt in sea water also determines the temperature at which sea water freezes. Adding salt to water lowers the freezing temperature.
Yet, despite the saltiness of the ocean, sea ice contains very little salt, about a tenth of the amount of salt that sea water has. This is because ice will not incorporate sea salt into its crystal structure. Therefore, sea ice is actually drinkable. The temperature and salinity of the sea water also help determine its density.
As the temperature of sea water decreases the density also increases. Also, as the salt content of sea water increases , so does its density.
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