1. Water Cycle and the Atmosphere

2. Where is water on Earth?
Reservoirs- protected artificial or natural lakes
Groundwater- water that collects underground

3. Water Cycle
The continuous movement of water from the atmosphere to the earth’s surface and back to the atmosphere again.
Aka: hydrologic cycle
Parts of the Water Cycle
Evaporation
Transpiration
Runoff
Ground Water
Condensation
Precipitation

5. Parts of the Water Cycle
Evaporation: liquid water changes into water vapor
Transpiration: plants give off water vapor into the atmosphere
Runoff: flows over land into rivers
Ground Water: water that soaks deep into the soil and rock underground
Condensation: water vapor cools into tiny liquid water droplets (clouds)
Precipitation : water falls from clouds to the earth’s surface (rain, snow, sleet, and hail)
Aquifer: Underground area of sediment and rocks that hold groundwater

7. What's in Earth's atmosphere?
This protective layer exists around Earth because our planet has just the right balance of size and distance from the sun.

8. The Atmosphere
Earth’s atmosphere is a layer of gases surrounding the planet, protecting and sustaining life.
It insulates us so that we don’t freeze at night.
Its ozone layer protects us from the sun’s ultraviolet rays.

9. Atmospheric pressure
Atmospheric pressure is a measurement of the force of air molecules in the atmosphere at a given altitude.
The pressure of the atmosphere changes as you rise above sea level.

10. Pressure changes with altitude

11. Parts of an Aneroid Barometer

12. Layers of the Atmosphere
Four Layers
Thermosphere
Mesosphere
Stratosphere
Troposphere*
The atmosphere is divided into layers based on temperature changes.
We live in the troposphere which is 0 to 11 kilometers above Earth's surface.

13. Layers of the Atmosphere
The four layers of the atmosphere include:
the troposphere, where we live;
the stratosphere, which contains the ozone layer;
the mesosphere, where meteors burn;
and the thermosphere, where satellites orbit Earth.

14. Energy in the Atmosphere
Our sun converts 5 million tons of its own mass into energy every second.
This process involves nuclear fusion.
Even though Earth intercepts only a tiny fraction of the radiation broadcast by the sun into space, this radiation provides most of Earth’s thermal energy.

17. Greenhouse effect
There are molecules in the atmosphere that act like the pebbles in the bucket.
They make it take longer for the infrared radiation to escape back into space compared to bucket with no pebbles.

18. Greenhouse effect
Adding greenhouse gases to the atmosphere is like adding more pebbles to the bucket.
It takes longer for radiation to escape from the atmosphere, so Earth’s average temperature rises.