Water in the Atmosphere

3. instrument used to measure relative humidity, uses 2 thermometers
5. a gray cloud that has a flat, uniform base and that commonly forms at very low altitudes
7. condition in which a substance is cooled below freezing point
8. solid particle in the atmosphere that provides surface for water vapor to condense onto
9. type of fog that forms when warm, moist air moves across a cold surface
10. feathery cloud that is composed of ice crystals and that has the highest altitude
11. process of introducing freezing nuclei or condensation nuclei into a cloud to cause rain to fall
12. type of fog that forms when cool air moves over an inland warm body of water
14. used to measure rainfall
19. precipitation in the form of lumps of ice
20. raindrops smaller than 0.5 mm in diameter
21. most common solid form of precipitation
23. formation of a large droplet by the combination of smaller droplets
24. temperature at which the rate of condensation equals rate of evaporation
26. process by which the temperature of an air mass decreases as the air mass rises and expands

1. ratio of amount of water vapor in air to the amount of water vapor needed to reach saturation at a given temperature
2. any form of water that falls to earth's surface
4. clear pellets that form when rain falls through freezing air
6. mass or water vapor per unit volume of air that contains water vapor
12. when a solid changes directly into a gas
13. heat energy absorbed or released during phase change
15. process by which the temperature of an air mass decreases as the air mass moves over a cold surface
16. low-level billowy cloud that commonly has a top that resembles cotton balls and a dark bottom
17. collection of small water drops or ice crystals suspended in air, formed when air cools and condenses
18. forms as rain freezes on the surfaces near the ground
22. liquid precipitation 0.5-5 mm in diameter
25. water vapor that has condensed very near the surface of earth, because the ground has cooled