Greenhouse Effect

As sunlight enters the Earth’s atmosphere, some of the radiation from the sun is reflected back into outer spaceBut, some of that radiation does not escape due to ‘greenhouse’ gases that reflect the radiation back in.

What are greenhouse gases?

Natural gases: water vapor, carbon dioxide, methane, nitrous oxide

Man-made gases: CFC’s (aerosols, styrofoam, refridgerants, air conditioners) as well as gases from smog

Greenhouse Gases over 150 yrs.

What are the effects?

1. If the amount of greenhouse gases has been increasing over the past 150 years due to the industrial revolution, how do you think that will affect the overall climate? WHY?

2. If the climate changes, what will happen to the biomes?

3. What will happen to the ecosystems within those biomes?

Heating Patterns

Standard 5a

Standard 5a

5a: Students know how differential heating of Earth results in circulation patterns in the atmosphere and oceans that globally distribute the heat.

Transfer of Energy on Earth

Remember that only 50% of sun’s energy reaches the Earth’s surface. Energy from the Sun reaches the Earth and heats it.Heat is then transferred through the atmosphere in three ways – radiation, conduction, & convection

Radiation, Conduction, Convection

Radiation: Energy transferred in the form of rays or waves.Conduction: Energy transferred when warmer objects come into contact with colder objects.Convection: Energy transferred by the flow of materials. Hot air and liquid rises up while cooler air sinks

Radiation

Convection

Conduction

Sun’s Intensity

Because the Earth is curved, the radiation from the Sun hits the Earth at different angles.Areas near the equator have direct sunlight (very hot)Areas at the poles have sunlight that is spread out (a lot cooler)

Sunlight

Most direct sunlight

Sunlight

Sunlight

Sunlight

90°N North Pole

66.5°N

23.5°N

0°

23.5°S

66.5°S

90°S South Pole

Arctic circle

Tropic of Cancer

Equator

Tropic of Capricorn

Arctic circle

Sun’s Intensity

Because the equator gets direct sunlight, the air gets hot and will riseA convection current happens where exiting hot air is replaced by cooler air from the polar regions.

Sun’s Intensity

Between the equator and the pole, there can be found three circulation patterns, or cellsHot air rises at the equator and at 60°Air sinks at 30°

Precipitation

Hot air also brings water vapor with it.As air cools, water vapor turns into clouds and eventually turns into rainfall, or precipitation.Precipitation usually found at the equator and around 60°

Seasons

The different amounts of sunlight and the tilt of the Earth causes the seasons.When the Northern hemisphere is tilted towards the sun (June), north experiences summer and south experiences winter.When the Southern hemisphere is tilted toward the sun (December), north experiences winter and south experiences summer.