Water in the Atmosphere By Kelsey Sullivan, Lance Reason, and Aaron Chapman T-3

Vocabulary Dew point-the temperature at which condensation begins. Condensation- the process by which molecules of water vapor in the air become liquid water. Psychrometer- has two thermometers, a wet-bulb thermometer and a dry- bulb thermometer.

More Vocabulary Humidity-is a measure of the amount of water vapor in the air. Relative Humidity- can be measured with a psychrometer. Evaporation- is the process by which water molecules in liquid water escape into the air as water.

The 3 Main Clouds Cumulus clouds are usually a sign of fair weather. Stratus clouds usually cover most of the sky. They also produce drizzle, rain or snow. Cirrus clouds only form at high levels, above about 6km.

How Clouds are Formed Clouds form when water vapor in the air cools to its dew point temperature, the temperature at which water vapor(gas) changes to a liquid or a solid. In order for condensation to occur, tiny particles must be present such as; dust, smoke, or salt.

Cirrus Clouds Cirrus clouds are wispy, feathery clouds. Cirrus clouds form only at high levels, above 6 kilometers, where temperatures are very low. Cirrus clouds are mostly made of ice crystals.

Stratus clouds The word stratus means spread out. Stratus clouds cover most of the sky. As stratus clouds thicken, they may produce drizzle, rain, or snow these clouds are called nimbostratus.

Cumulus clouds The word cumulus means heap, or mass. Cumulus clouds form less than 2 kilometers above the ground, but may grow in size and height until they extend upward as much as 18 kilometer.