Ocean Circulation

Components of the Climate System

• Atmosphere• Ocean

• Biosphere• Geosphere

Image from NASA

Atmosphere & Ocean Circulation

• Atmospheric Circulation– Depends on density

• Ocean Surface Circulation– Depends on the wind

• Deep Ocean Circulation– Depends on density

Why is Ocean Circulation Important?

• Transport ~ 20% of latitudinal heat

– Equator to poles

• Transport nutrients and organisms

• Influences weather and climate

• Influences commerce

Temperature Structure of Ocean

thermocline

Ocean Circulation

Wind-drive ocean surface currentsWind driven surface currents

• How fast? A few miles/hr (Gulf Stream off of Miami = 4.5 mph)

• How much? Total water in ocean surface circulation = about 100 Amazon Rivers (20 million m3/s).

Atmosphere & Ocean Circulation

• Atmospheric Circulation– Depends on density

• Ocean Surface Circulation– Depends on the wind

• Deep Ocean Circulation– Depends on density

Sea Surface Temperature

http://www.ldeo.columbia.edu/dees/ees/climate/slides/sst_march.gif

Ocean Salinity

http://www.ldeo.columbia.edu/dees/ees/climate/slides/sal_march.gif

•http://ingrid.ldgo.columbia.edu/

Temperature-Salinity (density) Diagram

Thermohaline Circulation

North Atlantic Deep Water

(NADW

15 million m3 of near surface water descend into the deep ocean each second.

Thermohaline Circulation - The Ocean Conveyor

Equatorial to polar heat transport and water flow

Ocean – Atmosphere Circulation

UNEQUAL HEATING OF EARTH

BUT – Outgoing solar radiation is not as uneven