OCN 5401 Chapter 6 Effect of Earth’s Rotation Instructor: Dr. George A. Maul / X 7453.

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Presentation transcript:

OCN 5401 Chapter 6 Effect of Earth’s Rotation Instructor: Dr. George A. Maul / X 7453

Average Global Winds

Satellite derived surface winds Satellite scatterometer

Inertial Oscillations

Rossby Number space time Ro=10 Ro=1 Ro=0.1 Ro=0.01

R o Balances ExampleAtmosphereRoOcean 1Tornado10River Plume 2Hurricane0.1G.S. Ring 3Westerlies0.001Drift Current 4Inertial Flow CnCn Rossby Waves

Meander motion

Baroclinicity baroclinic part barotropic part Laboratory Model 00

Pancake Ice – discovery of the Ekman Spiral

Ekman Spiral Coriolis balances Friction Ekman surface current is 45º to right of wind in northern hemisphere

Ekman’s Solution x y z left hand rule coördinates depth of frictional influence (where the subsurface flow is opposite to the surface flow U o ) surface speed

Ekman Mass Transport (M x ) and coastal upwelling f · M x = τ y Wind Stress = +τ y Mass transport is 90º to right of wind in northern hemisphere y x Wind Stress = -τ y

Ekman Transport and Marine Debris

Ekman Pumping Cold wake from Hurricane Bonnie, 1998

Global SST and Upwelling What’s happening at the equator?

Equatorial Upwelling

Air-Sea Interface Atmospheric Boundary Layer wind vector heights in meters

Sverdrup Mass Transport H.U. Sverdrup

Stommel’s Linear Model r b

Stommel’s Solution H.M. Stommel β-plane f-plane sea surface temperatures We learn that: Wind stress curl forces w.b.c. Internal friction closes streamlines β-effect causes w.b.c.

Portion of Franklin’s letter of 27 May 1762 Gulf of Florida, ca. 1827

To Sum It Up!

OCN 5401 Questions? Chapter 6