Atmospheric Heating

S6E4.a Demonstrate that land and water absorb and lose heat at different rates and explain the resulting effects on weather patterns.

• Describe what happens to solar energy that reaches Earth• Summarize the processes of radiation,

thermal conduction, and convection• Explain the relationship between the

greenhouse effect and global warming

Energy in the Atmosphere

• Earth and it’s atmosphere are warmed by energy from the sun.• We are going to discuss the three ways that this happens: radiation, conduction, and convection.

Radiation: Energy Transfer by Waves• RADIATION is the

transfer of energy as electromagnetic waves

• Radiation is how energy from the sun reaches Earth.

• Energy from the Sun is absorbed by the atmosphere, land, and water and converted into thermal energy

• The earth receives only about 2 BILLIONTHS of the energy radiated by the sun.

Radiation: Energy Transfer by Waves

Ex.Sun’s rays

traveling through space

to Earth.

Conduction: Energy Transfer by Contact

• THERMAL CONDUCTION is the transfer of thermal energy through a material by DIRECT CONTACT

• Thermal energy is always transferred from warm to cold areas

• When air molecules come into DIRECT CONTACT with the warm surface of earth, thermal energy is transferred to the atmosphere.

Conduction: Energy Transfer by Contact

In what ways have you

experienced conduction?

Think back….what is this called?

Convection: Energy Transfer by Circulation

Convection: Energy Transfer by Circulation

• CONVECTION is the transfer of thermal energy by the circulation or movement of a liquid or gas•MOST thermal energy in the atmosphere is transferred by CONVECTION

Convection: Energy Transfer by Circulation

• Circulation of hot & cold air: •As air is heated it becomes less dense and rises•Cool air is denser so it sinks•as the cool air sinks it pushes the warm air up.

• This cycle of warm air rising and cool air sinking causes a circular movement of air called a CONVECTION CURRENT

Greenhouse Effect

GreenhouseEffect

70% of the solar radiation which enters Earth’s atmosphere is absorbed by the clouds and Earth’s surface.

Likewise, the Earth’s surface re-radiates thermal energy. Most of this thermal energy is absorbed by gases in the atmosphere and radiated back to Earth’s surface instead of into space.

Greenhouse EffectWhat is the greenhouse effect? the warming of the surface and lower atmosphere of Earth that occurs when water vapor, carbon dioxide, and other gases absorb and reradiate thermal energy.

Greenhouse EffectAnd This: Atmosphere acts like glass walls and roof of a greenhouse, allowing solar energy to enter, but prevents thermal energy from escaping.

Greenhouse Effect

Greenhouse Effect

Global WarmingGlobal Warming: a gradual increase in average

global temperature due to the increase of greenhouse gases in the atmosphere that absorb thermal energy

What has increased the greenhouse gases?1. Increased use of fossil fuels= more

carbon dioxide in air 2. Deforestation-=less trees= more

carbon dioxide in air

Add carbon dioxide molecules to the airin your drawing.

Greenhouse Effect