where it all starts.. mars – too thin, so it doesn´t absorb enough heat venus – so dense, the...

THE SUN

Where it all starts.

OUR ATMOSPHERE ALLOWS OUR PLANET TO ABSORB THE PERFECT AMOUNT OF SUNLIGHT NEEDED FOR LIFE

Mars – too thin, so it doesn´t absorb enough heat

Venus – so dense, the heat doesn´t escape! Earth – the perfect combination!!!

Some of the sun´s energy is absorbed by the atmostphere

Some is absorbed by the planet´s land and water Some is reflected back into space If we keep polluting our atmosphere could become

thick and dense like Venus´s atmosphere!!!

HOW IS THERMAL ENERGY TRANSFERRED?

Radiation Electromagnetic waves (the sun´s heat arrives)

Conduction Direct contact (air touching warm land)

Convection Movement in gases & liquids Heat always rises because it is lighter/less dense What does this motion create?

The motion of wind and ocean currents!!!!

MOVEMENT OF AIR

Temperature differences are caused by the Earth´s curved surface

The equator gets a lot more heat than the North and South poles (obvio)

The motion is also affected by the Earth´s rotation

WIND SYSTEMS: SURFACE WINDS Trade winds - Near the equator all the wind blows

west and toward the equator. Prevailing westerlies

On either side of the trade winds, the prevailing westerlies blow opposite.

Always blow to the east (from the west) Always blow away from the equator

Polar easterlies - Polar winds always blowing west (from the east) and towards the equator (away from the pole)

See page 352 in text book

HIGH ALTITUDE WINDS: JET STREAMS Jet streams follow the prevailing

westerlies at their north and south border

Jet streams average between 97-185 km/hr

Just like sailors have used surface winds to sail their boats, pilots use jet streams If they are going east, they save gasoline

by going in the jet stream. If they are going west they avoid the jet

streams.

DAILY WINDS Land heats and cools faster than

water!!!! During the day air above the land is heated

by conduction The heated air…

Rises!!!! So at the beach in the day, there is a current

from the cool sea air going up. At night the air above land is cooler

So at the beach at night, there is a current going down towards the water.

SEASONAL WINDS: MONSOON During the winter, the land is much

colder than the ocean, so like the beach at night, the air moves away from the land.

During the summer, the land is much warmer so the wind blows in from the sea. This wind is usually full of moisture and brings a lot of rain.