Deep Ocean Currents 90% of the ocean’s water!

Depend on Density which is affected by Density which is affected by – temperature Colder water is more dense Colder water is more dense – salinity (how much salt is in the water) Saltier water is more dense Saltier water is more dense

Thermohaline circulation Refers to deep currents driven by differences in water temperature and salinity that arise from Refers to deep currents driven by differences in water temperature and salinity that arise from –1. heating/cooling at the sea surface –2. Adding or losing surface freshwater (evaporation and sea ice formation increase salinity; precipitation, runoff and ice-melt decrease salinity)

How does thermohaline circulation work? Transports huge volumes of cold, salty water from the North Atlantic to the Northern Pacific and brings warmer, fresher water in return. Transports huge volumes of cold, salty water from the North Atlantic to the Northern Pacific and brings warmer, fresher water in return.

Thermohaline circulation :Called the “Great Ocean Conveyer”

Oceans and the atmosphere interact to affect climate

The ITCZ: The Inter-tropical Convergence Zone

Evaporation,Precipitation and Oceans Trade winds carry evaporated water vapor to the Inter-Tropical Convergence Zone where it condenses as rain. Trade winds carry evaporated water vapor to the Inter-Tropical Convergence Zone where it condenses as rain.

What happens at the ITC Zone? Intense equatorial sun + warm ocean = heat + humidity As this air rises, it cools, and the water comes down in frequent thunderstorms As this air rises, it cools, and the water comes down in frequent thunderstorms

Coastal Climates and Oceans 1. Lands that get sideswiped by warm currents tend to have a lot of rain in addition to a fairly warm climate. 1. Lands that get sideswiped by warm currents tend to have a lot of rain in addition to a fairly warm climate. 2. Lands hit by cold currents tend to receive very little precipitation in addition to a comparatively cool climate. 2. Lands hit by cold currents tend to receive very little precipitation in addition to a comparatively cool climate.

Coastal climates and oceans 3. Water warms up and cools off much more slowly than land or air. 3. Water warms up and cools off much more slowly than land or air. 4. So coastal areas are insulated by nearby water and experience narrower temperature ranges. 4. So coastal areas are insulated by nearby water and experience narrower temperature ranges. 5. These Temperate climates have narrower temperature ranges and no extremes of precipitation. 5. These Temperate climates have narrower temperature ranges and no extremes of precipitation.temperatureprecipitationtemperatureprecipitation

EX: Maritime Temperate Climate Zone: Britain *Has cool summers and mild winters, smaller annual temperature range. *Strongly influenced by the ocean, which maintains fairly steady temperatures across the seasons. *Strongly influenced by the ocean, which maintains fairly steady temperatures across the seasons.

Ocean as CO 2 sink Oceans are the largest active carbon sink on Earth. Oceans are the largest active carbon sink on Earth. Increased CO 2 from human activities is warming the oceans causing ocean acidification and less mixing of nutrients Increased CO 2 from human activities is warming the oceans causing ocean acidification and less mixing of nutrients Major ocean currents could be affected Major ocean currents could be affected