Energy in our Atmosphere Our energy comes from the Sun in the form of waves…electromagnetic waves It reaches Earth in the form of visible light, infrared & UV radiation

3 Things happen to the Sun’s energy: 1. Absorbed 2. Reflected 3. Scattered

Absorbed by... Water vapor & other gases clouds dust particles land & water where it is changed into heat

Reflected... Back into space by clouds, dust, gas molecules

Scattered... Is the reflection of light in all directions

What happens to the energy turned into heat in our atmosphere? It’s transferred through: radiation conduction convection

Radiation Direct transfer of heat by EM waves Ex: heat from a campfire

Conduction Transfer of heat from one substance to another substance that is touching Ex: feet on hot sand

Convection Transfer of heat by the movement of fluid air liquid Ex: hot air traveling through vents from the furnace

All 3 heat the troposphere Convection causes most of the heating

What causes the wind to blow? the horizontal movement of air from an area of high pressure to an area of low pressure differences in air pressure which are caused by unequal heating in the atmosphere

How are winds described? By their speed & direction Ex: Northeasterly wind blowing at approx. 10miles per hour Wind speed is measured with an anemometer Wind direction is measured with a weather vane

2 types of winds: Local Global

Local Winds Winds that blow over short distances caused by unequal heating of Earth’s surface within a small area

Global Winds Winds that blow steadily from specific directions over long distances caused by unequal heating of Earth’s surface between the poles & the equator

Where do the global winds blow? Coriolis Effect the way Earth’s rotation makes the winds curve. Creates both wind belts & calm areas Northern Hemisphere-global winds curve to the right Southern Hemisphere-global winds curve to the left

Wind Belts: Trade Winds Prevailing Westerlies Polar Easterlies

Trade Winds blow from the horse latitudes toward the equator

Prevailing Westerlies winds that blow away from the equator towards the poles

Polar Easterlies Winds that blow away from the poles

Calm Areas: Doldrums Horse latitudes

Doldrums Regions near the equator with little to no wind

Horse Latitudes Calm areas of falling air at 30ºN and S latitudes

What about water in the atmosphere? Water Cycle movement of water between the atmosphere & Earth’s surface

Evaporation Process by which water molecules in water escape into the air as water vapor water into gas

Transpiration Evaporation of water from plants

Condensation Process by which molecules of water vapor in the air become liquid water gas into liquid

Precipitation Any form of water that falls from clouds & reaches Earth’s surface Common types: rain sleet snow freezing rain hail

What about the clouds? 3 types: cumulus stratus cirrus

Cumulus Clouds that look like fluffy, cotton balls usually indicate fair weather

Stratus Clouds that form in flat layers usually covering all or most of the sky

Cirrus Wispy, feathery clouds that form at high levels