Earth's Atmosphere and the Sun
A combination of heat transfers and energy conversions explains why the Sun is so important to Earth.
So, what is going on in the video below? It is all a matter of energy transfer, convection currents, and changes in air pressure!
Why is the Sun Important to Earth?
The Sun is the primary source of Earth's energy - it keeps the Earth warm and provides the basis of energy for food chains.
How does the Sun's energy reach Earth?
The sun's energy travels as electromagnetic waves (UV radiation, visible light, and infrared light) to Earth's surface.
What does the Sun's energy do on Earth?
- Some of the UV radiation is absorbed by the ozone layer, which protects the Earth
- The radiant energy heats the surface of the Earth
- The radiant energy causes water to evaporate, powering the water cycle
- The radiant energy is used by plants to conduct photosynthesis, which converts the Sun's energy into sugar! (chemical energy in food)
Terms to Review
Transfer of Thermal Energy
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Wind and Thermal Energy
Remember:
- Warm fluids have more energy, are less dense, have a lower pressure so they will rise
- Cooler fluids have less energy, are more dense, have a higher pressure, and sink or fill in space left by rising warm fluids
KEY TERM ALERT! Wind: Movement of air due to unequal heating of Earth’s surface - from high pressure to low pressure Measuring Wind: Anemometer Remember: Warm Air - Less Dense, Lower Pressure, Rises Cool Air - More Dense, Higher Pressure, Sinks/Fills spaces left by rising warm air General Wind Creation
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Global vs. Local Winds
Global Winds are consistent and help determine climate; uneven heating of Earth’s surface over large area
Local Winds change frequently (lasting a few minutes to a few days) and determine weather; uneven heating of Earth’s surface in local area
Climate vs. Weather
Climate - Typical atmospheric conditions over the long term in an area
Weather - Specific atmospheric conditions over a short period of time
Global Winds are consistent and help determine climate; uneven heating of Earth’s surface over large area
Local Winds change frequently (lasting a few minutes to a few days) and determine weather; uneven heating of Earth’s surface in local area
Climate vs. Weather
Climate - Typical atmospheric conditions over the long term in an area
Weather - Specific atmospheric conditions over a short period of time