Wind and Ocean Currents

Global windsOcean Currents

Local winds

Coriolis Effect

• Because the Earth rotates, and consists of a mixture of land and sea, the Coriolis Effect exists

• The Coriolis Effect is the movement of particles (such as air) to the right in the Northern Hemisphere

• How about the South?– They move to the left

Coriolis Effect

Air movement • Warm air raises; Cold air sinks moving into

the void left be the warm air • Air moves from high pressure to low

pressure

Global winds

What beltAre we in?Westerlies

Ocean Currents

• Surface Currents – In the upper 1000 m – Driven by temperature– Also know as the global ocean currents

• Density Currents – Driven by Density – More dense water sinks and where they

circulate for 500 to 2000 years

Surface Currents • Warm Currents

– Driven by Winds (temperature)– Flow away from the equator towards the poles

• Cold Currents – Driven by Winds (temperature)– Flow away from the poles towards the equator

• Counter Currents – Flow the opposite of the “wind” currents – They “Fill” in the gaps

Global ocean currents

Doldrums

• Windless zones at the equator • Air moves vertically

• And current-less zone in the middle of the major ocean basins

• Water mover around them

Local winds • Land Breeze • Cool air over the land • Warm air over water • Cold air slides into the

void left by the warm air rising

• Happens during nighttime

• Wind blowing from the land

• Sea breeze • Warm air over land • Cool air over water • Cold air slides into the

void left by the warm air rising

• Happens during daytime

• Wind blowing from the sea

CONVECTION

CONVECTIONMoves air in the atmosphere!

CONVECTIONWind over the shore changes direction

because of EARTH’S UNEVEN

WARMING & COOLING!

What About Convection in Water?

• Water and air are both fluids. • They both move due to convection!– Just like air, when liquid water is heated, it expands,

becomes less dense, and rises. Side note: Water is different, however, because of it’s unique

structure as a solid. Ice is actually less dense than liquid water whereas other substances are most dense as solids!

CONVECTION IN LIQUIDS!

Land Breeze

Wind

Land Breeze

Wind

Sea Breeze

Wind

Sea breeze

Wind