Table of Contents
How is thermohaline circulation caused?
The thermohaline circulation is mainly driven by the formation of deep water masses in the North Atlantic and the Southern Ocean caused by differences in temperature and salinity of the water.
What factors affect thermohaline circulation?
Thermohaline circulation describes the movement of ocean currents due to differences in temperature and salinity in different regions of water. Temperature and salinity change the density of water, resulting in the water to move accordingly.
Where does thermohaline circulation occur?
The basic thermohaline circulation is one of sinking of cold water in the polar regions, chiefly in the northern North Atlantic and near Antarctica. These dense water masses spread into the full extent of the ocean and gradually upwell to feed a slow return flow to the sinking regions.
What causes a Halocline?
A halocline is also a layer of separation between two water masses by difference in density, but this time it is not caused by temperature. It occurs when two bodies of water come together, one with freshwater and the other with saltwater. Saltier water is denser and sinks leaving fresh water on the surface.
How do humans affect salinity?
Human activities can cause salinization through the use of salt-rich irrigation water, which can be exacerbated by overexploitation of coastal groundwater aquifers causing seawater intrusion, or due to other inappropriate irrigation practices, and/or poor drainage conditions.
What is the meaning of thermohaline?
Definition of thermohaline : involving or dependent upon the conjoint effect of temperature and salinity thermohaline circulation in the Pacific.
Where does the halocline occur?
Haloclines are found in many areas around the world. They are common in areas where freshwater and saltwater come together, such as in estuaries, seaside caves, fjords, and of course, the oceans, more so in colder regions where cold water with a lower salinity “floats” on top of the salty warm layer.
What affects the halocline?
In oceanography, a halocline is a strong, vertical salinity gradient. Because salinity (in concert with temperature) affects the density of seawater, it can play a role in its vertical stratification. Increasing salinity by one kg/m3 results in an increase of seawater density of around 0.7 kg/m3.
How can human agriculture cause increased salinity to occur?
Irrigation salinity occurs due to increased rates of leakage and groundwater recharge causing the watertable to rise. Inefficient irrigation and drainage systems are a major cause of excess leakage and increase the risk of salinity and waterlogging in irrigation areas.
How does human activity affect ocean currents?
Human activities affect marine life and marine habitats through overfishing, habitat loss, the introduction of invasive species, ocean pollution, ocean acidification and ocean warming. It has been estimated only 13% of the ocean area remains as wilderness, mostly in open ocean areas rather than along the coast.
Why is downwelling important?
Downwelling also allows for deep ocean oxygenation to occur because these waters are able to bring dissolved oxygen down from the surface to help facilitate aerobic respiration in organisms throughout the water column.
What causes a halocline?
Which ocean currents are categorized as thermohaline?
Winds drive ocean currents in the upper 100 meters of the ocean’s surface. However, ocean currents also flow thousands of meters below the surface. These deep-ocean currents are driven by differences in the water’s density, which is controlled by temperature (thermo) and salinity (haline). This process is known as thermohaline circulation.
What are Thermohaline currents?
Thermohaline circulation. A summary of the path of the thermohaline circulation. Blue paths represent deep-water currents, while red paths represent surface currents. Thermohaline circulation (THC) is a part of the large-scale ocean circulation that is driven by global density gradients created by surface heat and freshwater fluxes.
What is thermal circulation?
Thermal circulations. many mesoscale phenomena are the result of a thermal circulation: thermal circulation – a circulation generated by pressure gradients produced by differential heating. thermal circulations tend to be shallow – do not extend up through the depth of the troposphere.