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Components of the Climate System Atmospher e Ocean Biosphere Geosphere Image from NASA

Ocean circulation

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Global ocean circulation patterns, adapted from Gilroy ECA presentation on ocean circulation. Website: gilroyeca.blogspot.com

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Page 1: Ocean circulation

Components of the Climate System

• Atmosphere• Ocean

• Biosphere• Geosphere

Image from NASA

Page 2: Ocean circulation

Atmosphere & Ocean Circulation

• Atmospheric Circulation– Depends on density

• Ocean Surface Circulation– Depends on the wind

• Deep Ocean Circulation– Depends on density

Page 3: Ocean circulation

Why is Ocean Circulation Important?

• Transport ~ 20% of latitudinal heat– Equator to poles

• Transport nutrients and organisms

• Influences weather and climate

• Influences commerce

Page 4: Ocean circulation

Temperature Structure of Ocean

thermocline

Page 5: Ocean circulation

Ocean circulation patterns – Wind

Page 6: Ocean circulation

Ocean circulation patterns – Surface Currents

Page 7: Ocean circulation

Ocean Circulation

Page 8: Ocean circulation

Winds and 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).

Page 9: Ocean circulation

Atmosphere & Ocean Circulation

• Atmospheric Circulation– Depends on density

• Ocean Surface Circulation– Depends on the wind

• Deep Ocean Circulation– Depends on density

Page 10: Ocean circulation

Sea Surface Temperature

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

Page 11: Ocean circulation

Ocean Salinity

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

Page 12: Ocean circulation

Temperature-Salinity (density) Diagram

Page 13: Ocean circulation

Thermohaline circulation

The Great Conveyor        The conveyor circulation transports heat to the North Atlantic. The sinking which takes place is susceptible to changes in surface salinity. If the surface of the North Atlantic gets too fresh, NADW won’t sink.

Global warming could increase melting of ice caps and sea ice, causing more fresh water to enter the Atlantic. Many models suggest that a shutdown of the conveyor would cause cooling over the North Atlantic and Europe.   The conveyor has been off in the past during global cold periods, such as the last ice age and during the Younger Dryas. One hypothesis is that the shutdown of the conveyor, coupled with resultant atmospheric changes, is enough to throw the world into an ice age - or at least a cold snap.

Page 14: Ocean circulation

Thermohaline Circulation

North Atlantic Deep Water

(NADW

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

Page 15: Ocean circulation

Thermohaline Circulation - The Ocean Conveyor

Page 16: Ocean circulation

Equatorial to polar heat transport and water flow

Page 17: Ocean circulation

Ocean – Atmosphere Circulation

Page 18: Ocean circulation

ENSOEl Niño/Southern Oscillation

3-7 year cycle of warming in E. Pacific

Page 19: Ocean circulation

ENSO

El Niño/Southern Oscillation

NASA/Goddard Space Flight CenterScientific Visualization Studio

Page 20: Ocean circulation

ENSO

El Niño/Southern Oscillation

http://svs.gsfc.nasa.gov/vis/a000000/a000200/a000287/index.htmlNASA/Goddard Space Flight CenterScientific Visualization Studio