What is Thermohaline Circulation?
Ocean circulation driven by seawater density in the ocean.
- Chinese name
- Hot salt circulation
- Foreign name
- thermohaline circulation
- Related terms
- Wind-driven circulation
- Subject branch
- Marine meteorology
- Ocean circulation driven by seawater density in the ocean.
Hot salt circulation description
- Thermal salt circulation is a thermodynamic ocean circulation system formed by uneven temperature distribution due to temperature and salinity changes caused by uneven heating and cooling of the ocean surface and uneven evaporation and precipitation. The hot salt circulation can transport heat, water and nutrients from the continent, and its existence and changes have a very important impact on the global climate system [1] .
Basic characteristics of hot salt circulation
- The area affected by the hot salt circulation is mainly concentrated in the deep layers of the ocean. Hot salt circulation is an ocean current forced by heat and freshwater fluxes [2] .
- A significant feature of the modern ocean hot salt circulation is the formation of deep water in the North Atlantic but not in the North Pacific. The deep-water source of the northern part of the modern Atlantic Ocean is very strong. It can cross the equator through the deep western border and eventually enter the Southern Ocean. It merges with the deep waters of the Weddell and Ross Seas, and then rises into the vast Indian Ocean and Pacific Ocean [3] .
- The hot salt circulation is a cold water circulation, and its situation is related to the formation and distribution of oceanic water masses. In polar seas, as the latitude increases, the upper seawater cools rapidly, the density increases and it sinks violently, becoming the main source of middle, deep and bottom water in the ocean. Among the bottom water masses, the most famous is the bottom water of the Antarctic, which floods the bottom of the global ocean. Antarctic bottom water is mainly formed in the Weddell and Ross Seas in winter.
- Deep water masses are the thickest water masses in the world's oceans, and their volume accounts for about 30% of global seawater. The most famous of these is the deep water of the North Atlantic. Studies have shown that the low-temperature, low-salt deep water that overflows from the Greenland and Norwegian Seas forms deep water in the eastern North Atlantic, and the seawater that overflows from Greenland-Iceland forms deep water in the western North Atlantic.
The importance of hot salt circulation
- American oceanologist Stommel believes that the temperature difference between the upper ocean equator and the polar region drives the hot salt circulation in the deep ocean. There are different states of the hot salt circulation in the ocean. When the hot salt circulation changes from one state to another, Can cause sudden changes in climate. The hot-salt circulation plays an extremely important role in the climate system, it plays a vital role in regulating the earth's climate system, and may be one of the factors triggering the abrupt climate change [3] . The importance of the hot salt circulation is that it, together with the meridional circulation system of the atmosphere, constitutes the meridional circulation system of the entire earth's climate system.