– If global warming shuts down the thermohaline circulation in the North Atlantic Ocean, the result could be catastrophic climate change . ... Between Greenland and Norway, the water cools, sinks into the deep ocean, and begins flowing back to the south.
What would happen if circulation stopped?
If the currents were to stop completely, the average temperature of Europe would cool 5 to 10 degrees Celsius . There would also be impacts on fisheries and hurricanes in the region. The currents in the North Atlantic are part of a global pattern called thermohaline circulation, or the global ocean conveyor.
Why is the thermohaline circulation so important?
Thermohaline circulation plays an important role in supplying heat to the polar regions . Therefore, it influences the rate of sea ice formation near the poles, which in turn affects other aspects of the climate system (such as the albedo, and thus solar heating, at high latitudes).
What is the danger of disrupting the thermohaline oceanic conveyor system?
Global climate change could disrupt the global conveyer belt, causing potentially drastic temperature changes in Europe and even worldwide. The global conveyor belt is a strong, but easily disrupted process. Research suggests that the conveyor belt may be affected by climate change.
How is thermohaline circulation disrupted?
Wind-driven surface currents (such as the Gulf Stream) travel polewards from the equatorial Atlantic Ocean, cooling en route, and eventually sinking at high latitudes (forming North Atlantic Deep Water). This dense water then flows into the ocean basins.
What happens if AMOC slows?
As the current slows down, this effect weakens and more water can pile up at the US east coast , leading to an enhanced sea level rise.” In Europe, a further slowdown of the AMOC could imply more extreme weather events like a change of the winter storm track coming off the Atlantic, possibly intensifying them.
What happens if AMOC shuts down?
If the AMOC does completely shut down, the change would be irreversible in human lifetimes , Boers said. The “bi-stable” nature of the phenomenon means it will find new equilibrium in its “off” state. Turning it back on would require a shift in the climate far greater than the changes that triggered the shutdown.
What is thermohaline circulation caused by?
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. In the Earth’s polar regions ocean water gets very cold, forming sea ice.
What is thermohaline circulation mainly due to?
As opposed to wind-driven currents and tides (which are due to the gravity of moon and sun), the thermohaline circulation (Fig. 1) is that part of the ocean circulation which is driven by density differences . Sea water density depends on temperature and salinity, hence the name thermo-haline.
How does temperature 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. Cold water is usually denser than warm water (4°C is where water is densest).
What will happen if Gulf Stream stopped?
It would disrupt monsoon seasons and rains in places like India, South America and West Africa , affecting crop production and creating food shortages for billions of people. The decline of the Amazonian rainforest and the Antarctic ice sheets would also be put into fast forward.
Is the thermohaline circulation slowing down?
The Thermohaline Circulation influences the climate all over the world. A shutdown or slowdown of the thermohaline circulation is a hypothesized effect of global warming on a major ocean circulation . A 2015 study suggested that the Atlantic meridional overturning circulation (AMOC) has weakened by 15-20% in 200 years.
How long does thermohaline circulation take?
Lecture notes from one of Columbia University’s 2007 “The Climate System” class suggests this process takes between 100-1000 years . This paper says Thermohaline Circulation overturns deep water every 600 years or so.
What causes deep ocean circulation?
In contrast to wind-driven surface currents, deep-ocean currents are caused by differences in water density . The process that creates deep currents is called thermohaline circulation—“thermo” referring to temperature and “haline” to saltiness. ... This water also cools and sinks, keeping a deep current in motion.
Why is the AMOC weakening?
The Atlantic Meridional Overturning Circulation (AMOC), a tipping component of the climate system, is projected to slowdown during the 21st century in response to increased atmospheric CO 2 concentration . The rate and start of the weakening are associated with relatively large uncertainties.
What ocean current is slowing down?
The study, which appeared in the journal Nature Climate Change, found several signs that Atlantic Meridional Overturning Circulation (AMOC), of which the Gulf Stream is a part, is slowing down and might be about to collapse.
