Atmosphere Flashcards
What is atmosphere
The atmosphere that surrounds the earth is a mixture of gases
The layers of atmosphere in order going up
Troposphere, stratosphere, mesosphere, thermosphere
Troposphere
Contains most of the earths gases and water vapour
Percentages of gases
Nitrogen : 78%
Oxygen : 21%
Other gases (water vapour, carbon dioxide) : 1%
How does the atmosphere influence the earth
It is the air we breathe
It absorbs heat from the sun
It retains heat at night
It protects us from the dangerous rays of the sun
It is where the weather is formed (the troposphere)
How is the atmosphere heated
The Suns solar energy is the main source of heating the earth
- The Suns rays heat the earth
- The earth then heats the atmosphere around it
- Some heat remains and some escapes
What causes the unequal heating of the earth
Places near the equator are warmer than places North or south of the equator. This is caused by latitude and the tilt of the earth
How the sun heats the earth : latitude
Near the equator
The suns rays heat a small area.
The Suns Rays travel through less atmosphere so they do not lose much heat.
This makes the area around the equator hotter than the north or South
How the sun heats the earth : latitude
Away from the equator
The Suns Rays spread out, heating a wider area
The Suns Rays travel through more atmosphere, so they lose heat here
This makes the areas further away from the equator cooler
The tilt of the earth : Northern summer
Northern hemisphere is tilted towards the sun
This means longer days, more heat from the sun, winter in the Southern Hemisphere
The tilt of the earth : Northern winter
The northern hemisphere is tilted away from the sun
This means longer nights, less heat from the sun, summer in the Southern Hemisphere
What is the greenhouse effect
The earths atmosphere holds onto some energy from the sun. This is called the greenhouse effect. It supports plant and animal life
What is global warming
More greenhouse gases (CFC’s, methane, carbon dioxide) are being produced into the atmosphere. They control how much heat the earth retains and as they increase, the earth is getting warmer. This is global warming.
Causes of global warming
More trees are being cut down in forests in Brazil, so there are less trees to absorb the carbon dioxide
There are more CFC’s being produced as a greater use of aerosols, plastics and fridges
More fossil fuels (oil, gas, coal) are being burned in power stations and factories which increases carbon dioxide.
Effects of global warming
Water shortages will result in crop failure and famine.
Polar ice caps are melting which causes sea levels to rise which will cause floods in low lying countries.
Tropical diseases like malaria will spread to warmer countries
Some counties will get a mild climate so they will produce more food.
The desert is spreading, ruining some African countries
