Ocean surface currents function of wind duration, intensity, and fetch; Coriolis effects;...

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Transcript of Ocean surface currents function of wind duration, intensity, and fetch; Coriolis effects;...

• Ocean surface currents function of wind duration, intensity, and fetch; Coriolis effects; continental position; water density and salinity

• Climatic changes: a matter of periodicity; interaction of atmosphere, ocean and land– Short

cycle changes: North Atlantic Oscillation

• Short term oscillations: Arctic Oscillation

• Longer scale oscillations: El Nino Southern Oscillation– Neutral phase below

• “Warm phase”

• Sea surface temperatures (SST) and ENSO

• La Nina conditions

• More long-term oscillations: Pacific decadal oscillation (PDO)

• Multidecadal oscillation: Atlantic multidecadal oscillation

• Importance of deep ocean curents: The Global Conveyor Belt of Walter Broecker

About 12,000 ybp, sudden drop in temperature, some re-advance of ice sheets in North America – Younger Dryas period

• At same time, icebergs dropped boulders in North America- Heinrich events

• Heinrich events now thought to be due to drainage patterns from North America – glacial Lake Agassiz– Theorized shutdown of thermohaline circulation, drop in

temperature of North America and Europe

• Paleoclimatology and paleobiogeography• http://www.youtube.com/watch?v=USIAcXfv39k• how do we study paleobiogeography?

– Use of tree cores– Use of pollen cores

• Ice cores and climate determination

• Measuring changes from millions of years ago– http://www.youtube.com/watch?v=iAa0fNTgQyw

• Changes in climate over millions of years

• Influence of continental position – theory of plate tectonics– Example of North and South America – isthmus of Panama

• Disruption of Pacific-Atlantic connection; formation of Gulf Stream to flow to the northeast

THEY THAT GO DOWN TO THE SEA IN SHIPS, that do business in great waters; These see the works of the LORD, and his wonders in the deep. For he commandeth, and raiseth the stormy wind, which lifteth up the waves thereof. They mount up to the heaven, they go down again to the depths: their soul is melted because of trouble. They reel to and fro, and stagger like a drunken man, and are at their wits' end. Then they cry unto the LORD in their trouble, and he bringeth them out of their distresses. He maketh the storm a calm, so that the waves thereof are still. Then are they glad because they be quiet; so he bringeth them unto their desired haven.

Psalms, 107:23-30, KJV