Unit 5: The Atmosphere & the Weather

The Atmosphere

The atmosphere is a layer of air that surrounds the Earth. Clouds form in the atmosphere. The atmosphere regulates electrical and magnetic forces. It absorbs energy from the sun and protects us from solar radiation and the cold of space.

Air

Air is all around us. Air is a mixture of gases; mostly nitrogen and oxygen. It also contains water vapour.

Wind

The air is always moving. Wind is air in motion. During the day the sun warms up the Earth and the air in the atmosphere. When air gets warmer, it rises because it is lighter than cold air. Cold air enters the space abandonded by the warm air.

The Five Layers of the Atmosphere

Troposphere

The troposphere provides the weather. In this layer the Earth absorbs the Sun's energy and heats the air. When warm air rises it forms clouds. Warm air also causes rain and wind.

Stratosphere

The Stratosphere is the layer where jet planes fly. The ozone layer is also in this layer. The ozone absorbs harmful ultraviolet rays from the Sun.

Mesosphere

The mesosphere layer is the coldest layer of the atmosphere. Sometimes we can see meteors in this layer.

Thermosphere

The thermosphere is where beautiful aururas occur. It is also the layer where astronauts orbit the Earth.

Exosphere

The exosphere is the upper layer of the atmosphere. In this layer matter escapes into space.

Online Activities

Quiz game

http://calipsooutreach.hamptonu.edu/atrivia.swf

Atmosphere game

http://calipsooutreach.hamptonu.edu/atmosphere.swf

Atmosphere launch

http://www.glencoe.com/sites/common_assets/science/virtual_labs/ES14/ES14.html

The Elements of Weather

When we measure temperature, we measure the heat or cold in an object or substance. When the temperature is high, we feel warm. When it is low, we feel cold.

Wind

Wind is air in motion. Wind is caused by differences in air temperature in the atmosphere.

Humidity

Humidity is the amount of water vapour in the air. When humidity is low, the air feels dry. When humidity is high, the air feels wet.

Rain

Rain is a type of weather precipitation. The heat fro the Sun evaporates water from oceans, lakes and rivers. Water vapour rises and expands to form clouds. When the water in clouds cools, it rains.

Measuring the Weather