EARTH'S ATMOSPHERE

3. a line on a weather map that joins places that have the same temperature.
6. fluffy,white clouds, usually with flat bottoms, that look like rounded piles of cotton.
8. a giant wave usually caused by an earthquake beneath the ocean floor.
9. an instrument used to measure changes in air pressure.
10. an instrument used to measure wind speed.
11. any form of water that falls from clouds and reaches Earth's surface.
15. clouds that form in flat layers and often cover much of the sky.
17. an instrument used to measure temperature.
18. the temperature at which condensation begins.
20. the boundary where unlike air masses meet but do not mix.

1. An instrument used to measure precipitation.
2. an instrument used to measure relative humidity.
4. a small storm often accompanied by heavy precipitation and frequent thunder and lightning.
5. wispy,feathery clouds made of ice crystals that form at high levels.
7. scientists who study the causes of weather and try to predict it.
12. a rapidly whirling, funnel-shaped cloud that reaches down to touch Earth's surface.
13. a tropical storm that has winds of about 119 kilometers per hour or higher.
14. amount of water vapor in a given volume of air.
16. the condition of Earth's atmosphere at a particular time and place.
19. a line on a weather map that joins places that have the same air pressure.