The impact of changes in the ocean overturning circulation on climate has become a hot topic today as global temperatures rise and melting sea ice and glaciers add freshwater to the North Atlantic.ptpbydgoszcz.pl/components/what-to-expect-when-dating-a-german-guy.php
Enjoying EarthSky? Subscribe.
A study suggested that cooling in the North Atlantic may be due to a reduction in the overturning circulation, while a study suggested there had not been enough freshwater to have an effect. The new study explores what happened to ocean circulation when the earth went through a series of abrupt climate changes in the past during a time when ice covered part of North America and temperatures were much colder than today. It looks at the Atlantic meridional overturning circulation, which distributes heat as it moves warmer surface water from the tropics toward Greenland and the high northern latitudes and carries colder, deeper water from the North Atlantic southward.
Using chemical tracers in sediment that builds up on the sea floor over time, Henry and his coauthors were able to document the relative speed of the Atlantic meridional overturning circulation during each abrupt climate change during the last ice age.
Thermohaline circulation - Wikipedia
The chemical tracers show that the speed of the ocean overturning circulation changed first, and that sea surface temperature changed a while later. That suggests that cooling may start with changes in the ocean circulation, influencing the northern sea surface and atmosphere, said co-author Jerry McManus , a professor at Lamont-Doherty Earth Observatory. A new study using sea floor sediment from the North Atlantic connects a series of abrupt climate changes during the last ice age with changes in the ocean overturning circulation.
The scientists stress that more work is needed to determine whether changes in ocean circulation initiated the abrupt climate changes or were an intermediary effect initially triggered by something else. The instability appears to occur only in certain temperature ranges, and when there is a large amount of land ice that could contribute freshwater.
There is constant motion in the ocean in the form of a global ocean conveyor belt due to thermohaline currents. These currents are density driven, which are affected by both temperature and salinity.
- Faith Shaping Ministry.
- Bring Her Down: How the American Media Tried to Destroy Sarah Palin?
- Ocean circulation.
- Ocean Circulation (labeled currents) Dataset | Science On a Sphere;
Cold, salty water is dense and sinks to the bottom of the ocean while warm water is less dense and rises to the surface. The "start" of the ocean conveyor belt is in the Norwegian Sea.
Warm water is transported to the Norwegian Sea by the Gulf Stream. The warm water provides heat for the atmosphere in the northern latitudes that gets particularly cold during the winter.
- Writers on Leadership (Penguin Business).
- William Shatner Presents: The Tekwar Chronicles #2?
- All I Want for Christmas is A Bedpan!
- Global Ocean Circulation.
- Ocean current!
- Sonata c minor K302 - Keyboard.
- Beiträge zur Entdeckung und Erforschung Afrikas (German Edition)?
This loss of heat to the atmosphere makes the water cooler and denser, causing it to sink to the bottom of the ocean. As more warm water is transported north, the cooler water sinks and moves south to make room for the incoming warm water.
This cold bottom water flows south of the equator all the way down to Antarctica. Search in this book.
This second edition retains the general structure of the first edition, but has been updated in the light of recent oceanographic research, and improved as a teaching text on the basis of feedback from past students and other readers. In the final Chapter, treatment of water mass formation has been updated to reflect recent ideas about the processes involved and how they relate to climatic change over different time-scales, from decades to millennia.
High quality full colour diagrams Substantial chapter summaries ideal for revision Answers, hints and notes for questions at back of the book.