Lecture 4: OCEANS (Outline)

The State of Oceans

Potential Temperature

Salinity

Density

Density and Temperature and Salinity

Vertical Structure of Ocean

Mixed Layer Processes

Seasonal Variation of Mixed Layer

Two Circulation Systems

Global Surface Currents

Six Great Current Circuits in the World Ocean

Characteristics of the Gyres

Major Current Names

Gulf Stream

Surface Current – Geostrophic Gyre

Step 1: Surface Winds

Winds and Surface Currents

Step 2: Ekman Layer
(frictional force + Coriolis Force)

Ekman Spiral – A Result of Coriolis Force

Formula for Ekman Transport

How Deep is the Ekman Layer?

Ekman Transport

Mixed Layers in the Atmosphere and Ocean

Step 3: Geostrophic Current
(Pressure Gradient Force + Corioils Foce)

Ekman Transport à Convergence/Divergence

Geostrophic Current

Step 4: Boundary Currents

Boundary Currents

Eastern Boundary Current

Costal Upwelling/Downwelling

Interior Upwelling / Downwelling

Deep Ocean Circulation: Density-Driven

Thermohaline Circulation

Two Regions of Deep Water Formation

Ocean Water Mass

Thermohaline Conveyor Belt

Thermohaline Conveyor Belt