1. Earths Systems

2. Atmosphere
Invisible layers of air primarily made up of Nitrogen (75%), Oxygen (20.9%), and Argon (.9%) gases.

3. troposphere
Zone where weather occurs; a dense layer of air in which molecules are fueled by sunlight and create energy for weather.

4. barometer
Measures the pressure of air pushing down on the tube of mercury.

5. Wind vane
Measures the direction of the wind.

6. anemometer
Measures wind speed.

7. Rain gauge
Measures the amount of rain.

8. Greenhouse effect
Radiation from the sun is reflected by earth and then bounced in to the atmosphere where the water particles in the air trap the heat. The water particles remain in the troposphere causing the lowest layer of atmosphere to be warmer.

9. Low pressure
Causes cloudy and rainy weather. Rapid low pressure changes cause storms.

10. Cumulus clouds Moist air collects rapidly over a small area.
Cumulonimbus clouds cause thunderstorms.

11. Stratus
Air rising gently over a large area and then cools slowly. Makes sunlight seemed filtered. They contain ice crystals that can make the sun or moon appear to have a halo.

12. cirrus
High in the atmosphere and look wispy. They form when water vapor condenses directly in to ice crystals.

13. Air masses
Large areas of air with the same temperature and moisture levels of the surface.

14. Cold air mass
Produces cold weather.

15. Warm air mass
Produces warm weather.

16. Maritime air mass
Moist air that forms over the ocean.

17. Continental air mass
Dry air that forms over the continents.

18. Cold Front
Leading edge of a cold air mass. These fronts bring snow, thunderstorms, and heavy rains.

19. Warm front
Leading edge of a warm air mass. These bring rainy weather followed by clear weather.

20. Ocean currents Large rivers of water flow through the ocean.
Cold Currents- run deep below the surface and creep along the bottom of the ocean until they reach the tropics.
Warm Currents- water heated by the sun and are pushed along by steady winds from the equator.

21. Jet stream
Fast moving air

22. Gulf stream