Deep Ocean Circulation

Significant vertical movement ▫Accounts for the thorough mixing of deep- water masses

Density Currents Vertical movement of water that results from density differences Dense water sinks and spreads out beneath the ocean’s surface Increased density caused by:  decrease in temperature  increase in salinity

High Latitudes (decrease in temps.)  where most deep currents begin  sea-ice is formed due to cold temps., leaving behind a greater salinity of remaining water, which then sinks  highest density of ocean water found near Antarctica  ocean water sinks and travels the ocean basin for some years

Evaporation (increases in salinity)  high temps. - increase evaporation  l ess water leads to greater salinity of remaining water  remaining water sinks to ocean basin and travels the globe

Conveyor Belt – Thermohaline Circulation  the circulation of ocean water around the globe  from the Atlantic through the Indian and Pacific and back

Circulation involves a warm surface current and a cool underlying current  warm surface water flows towards the poles  at the poles water temp. drop - salinity increases making it more dense and it sinks  sinking water then moves towards the equator on the ocean floor

 at the equator the water is cold and deep  deep water eventually upwells to complete the circuit – ▫ influences global climate by warm water releasing heat into the atmosphere

What would happen if thermohaline circulation were to stop?