tailieunhanh - Geography and Oceanography - Chapter 14

How does the Deep Ocean respond to Surface Circulation? The main gyres move heat and salt, Resulting DENSITY variations lead to vertical flow (sinking), Formation of“water masses”, characterized by Temperature + Salinity = Density,Density Variation in Sea densest seawater is cold and salty This is formed at high latitudes in the North and South Atlantic: | Deep Ocean Circulation Motion in the Ocean, Part 2, “The Great Conveyor Belt” Jack Barth (barth@) NASA web site: Surface Circulation Surface and Deep Ocean Circulation help move heat from equator to pole Atmosphere & Ocean each responsible for about half of heat transfer How does the Deep Ocean respond to Surface Circulation? The main gyres move heat and salt Resulting DENSITY variations lead to vertical flow (sinking) Formation of “water masses”, characterized by Temperature + Salinity = Density Density Variation in Sea Water Isopycnals = constant density Density Variation in Sea Water Nearly all the water in the oceans is cold North Atlantic Surface Circulation Density-Driven Water Flow Called “Thermohaline Circulation”, because temperature and salinity together determine density of seawater “Thermo” = temperature “haline” = salt Where does the Ocean’s Deepest Water Come From? The densest seawater is cold and salty This is formed at high latitudes in the North and South Atlantic: North Atlantic Deep Water (NADW) Antarctic Bottom Water (AABW) Density of Sea Water * * NADW AABW Density Rules! NADW AABW Deep Water Masses NADW Deep/bottom water formation sites Antarctic Bottom Water (AABW) in Weddell, Ross Seas and Adelie Coast North Atlantic Deep Water L. Talley (SIO) Antarctic Bottom Water (AABW) Weddell Sea major site of AABW formation AABW circles Antarctica and flow northward as deepest layer in Atlantic, Pacific and Indian Ocean basins AABW flow extensive 45°N in Atlantic 50°N in Pacific 10,000 km at km h-1; 250 y North Atlantic Deep Water (NADW) Coastal Greenland (Labrador Sea) site of NADW formation NADW comprises about 50% of the deep water to worlds oceans NADW in the Labrador Sea sinks directly into the western Atlantic NADW forms in Norwegian Basins Sinks and is dammed behind sills Between Greenland and Iceland and Iceland and the British Isles NADW periodically spills over sills into the North . | Deep Ocean Circulation Motion in the Ocean, Part 2, “The Great Conveyor Belt” Jack Barth (barth@) NASA web site: Surface Circulation Surface and Deep Ocean Circulation help move heat from equator to pole Atmosphere & Ocean each responsible for about half of heat transfer How does the Deep Ocean respond to Surface Circulation? The main gyres move heat and salt Resulting DENSITY variations lead to vertical flow (sinking) Formation of “water masses”, characterized by Temperature + Salinity = Density Density Variation in Sea Water Isopycnals = constant density Density Variation in Sea Water Nearly all the water in the oceans is cold North Atlantic Surface Circulation Density-Driven Water Flow Called “Thermohaline Circulation”, because temperature and salinity together determine density of seawater “Thermo” = temperature “haline” = salt Where does the Ocean’s Deepest Water Come From? The densest seawater is cold and salty This is formed at high .