- The role of the Sun
- Effect on Weather
- Why do we have temperature
- How do we measure air temperature?
Sun is the ultimate source of heat energy of the earth. All the
Earth's heat and light comes from the Sun. The heat and light reaches
the Earth from the Sun in one minute is more than the amount of
the whole world can produce in a year.
Sun keeps the temperature of most of the Earth' surface at -51 to
49 degrees Celsius. Most living things can only survive at 0 to
49 degrees Celsius. If the amount of sunlight reaching the Earth
was cut by one tenth, the oceans would turn to ice and life on Earth
Sun is the key to the world's weather. Its rays filter through the
atmosphere and warm the Earth's surface which, in turn, heats the
air above. This makes the air move because warm air rises. As the
rising warm air moves farther away from the land, it cools and sinks.
Air moves all over the world, causing winds which carry weather
changes. Also, the Equator is hot because the Sun shines directly
overhead. The Poles are cold because the rays hit the Earth at lower
People used to think that the closer you went to the Sun, the hotter
it would be. But as hot air rises it expands and cools, so the higher
places on the earth you go the colder it is. Air cools by 3 degrees
Celsius for every 305m it rises. This is why the tops of mountains
Earth absorbs sunlight and then releases it into the air again as
heat. The heat is trapped by water vapour and clouds in the atmosphere
and reflected back to Earth. The atmosphere acts like an enormous
blanket around the Earth, keeping the warmth.