Physical Geography 101
Poleward Transport of Heat

Poleward Transport of Heat

Where is greatest amount of solar radiation received on Earth?
Where is least amount of solar radiation received on Earth?

Energy Surplus - Deficit

Low latitudes
– energy surplus
– energy gained > energy lost
High latitudes
– energy deficit
– energy gained < energy lost
Global Energy Balance on a global scale
Excess energy moved from low latitudes to high latitudes

Heat Transport

2 methods:

Ocean Circulation

Surface Currents:
– Tropical water moves to poles.
– Arctic water returns to tropics.
Warm water loses counterradiation energy.
Vertical Circulation
– currents created by changes in density.
Warm equatorial water moves poleward
– evaporation occurs
Water cools and salinity increases.
– density increases
Increased density causes water to sink at high latitudes.
Bottom current returns to tropics.

Ocean Currents

Surface ocean currents are driven by atmospheric circulation due to friction.
Not all energy is transferred

Coriolis Effect on Ocean

Ocean currents are deflected to right in Northern Hemisphere
To left in Southern Hemisphere.

Ocean Gyres - Currents

Large circular currents due to Subtropical High Pressure Belt

Ekman Spirals

Upwelling Currents