Thread by @dbirch214

1.There are three main mechanisms for heat transport.
In the atmosphere, through the movement of warm and cold air masses (winds)as latent heat in water vapour: water evaporates from oceans in the tropics and is released at higher latitudes when the vapour condenses into clouds.

2. The system of surface and deep currents that cools the tropics and warms high latitudes is sometimes called the global conveyor because it acts as a giant conveyor belt that transports heat, salt, nutrients and dissolved gases such as carbon dioxide and oxygen around Oceans.

3..you will recognise the map attached . It shows the wind driven circulation with its five subtropical gyres, the Antarctic Circumpolar Current, and two subpolar gyres in the northern hemisphere.

4..In contrast to the wind driven circulation the THC also involves flow in the deep ocean. It is the result of water cooling and sinking at high latitudes, and slowly returning to the surface through vertical mixing. The journey around the conveyor typically takes hundreds yrs.

5..Where does deep water form by sinking from the surface? If ‘new’ deep water is water that has recently left the surface, in which ocean do you find the oldest deep water? How does the Atlantic's role in the THC differ from those of the Pacific and Indian oceans?

6..In the figure deep water forms in the North Atlantic. The deep water travels from the Atlantic via the Southern Ocean into the Indian Ocean and then into the Pacific, so the 'oldest' deep water is found in the Pacific.Deep water forms only in the Atlantic.

6 cont..
The main vertical circulation brings deep water to the surface in the Pacific and Indian oceans.
The surface ocean - the layer influenced by the wind - is in constant exchange with the atmosphere.

7...
Heat- moisture and gases such as oxygen and carbon dioxide flows between the two over periods of days to a few years. The surface ocean is only a few hundred metres deep. Beneath lies the deep ocean, where the water is very cold and dense. This prevents it "Exchange".

8..
Between  the surface and deep ocean is the thermocline, a layer of water down to about 1000m, where the temperature decreases rapidly with depth. The thermocline acts like a lid on the deep ocean, keeping the cold, CO2 -and nutrent-rich deep water from returning to the sfc.

9..
Water in the deep ocean is very cold and dense. To replace it, surface water must be sufficiently salty and cold to match the density of the deep water.
Satellite SST and currents. Stars show areas of deep-water formation.⤵

10..
Looking at the vertical structure of Atlantic water (above), at what latitudes does deep water form? How does this relate to the thermocline?
A1.
Deep water forms at high latitudes (typically north and south of 60°) in both the southern and northern hemisphere's.

10..
A2. .In the North Atlantic the temperatures in the sinking region are typically less than 4°C. In the Southern Ocean the temperatures are typically around 0°C or less. This means AABW (formed in the Antarctic) is colder and denser than NADW (formed in the North Atlantic).

11..As the warm surface water from the Gulf Stream crosses the Atlantic, most of it turns south at about 40°N, but some continues towards the northwest (see figure).

12..The eastern branch continues past Scotland, and starts to sink in the Nordic Seas - the ocean between Greenland, Iceland and Norway. This cold, dense North Atlantic Deep Water (NADW) returns south at depth. northern branch circles the subpolar gyre and enters Labrador sea.

13..The last remains of the warm, salty water from the Gulf Stream flows on towards the Arctic. In the Barents Sea it is responsible for the ice free conditions in the Russian port of Murmansk.
Not CO2 not you however great ocean transport.
End.