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

Why is Ocean Circulation Important? Transport ~ 20% of latitudinal heat Equator to poles Transport nutrients and organisms Influences weather and climate Influences commerce 4 th century BC ,Pytheas of Massalia, a Greek ship captain, explored eastern Atlantic Okeanos (Greek for “Great River”) because he found the ocean flowing south (Canary Current) and thought it was a river too wide to cross.

Temperature Structure of Ocean thermocline

Ocean Circulation

Wind-drive ocean surface currents Wind driven surface currents Wind-drive ocean surface currents London = 51 deg N James Bay = 51 deg. N Edinburgh = 55deg N, same latitude as Ontario’s Polar Bear Provincial Park Total water in ocean surface circulation = about 100 Amazon Rivers (20 million m3/s). It requires 500-2000 years to complete cycle. 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

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

Ocean Salinity AVERAGE = 35 ppm or 3.5% denser 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 M&M fourth edition, solar constant = rate of solar radiation on surface perpendicular to the sun’s rays at the top of the atmosphere, 1.97 cal/cm2/min or 1372 watts/m2 Difference between perihelion (2.04 cal/me/min) vs 1.91 cal/m2/min at aphelion 1 watt/hr = 860 cal