1. Abney Elementary Mrs. Delaup

2.  The atmosphere is a thin blanket of air that surrounds the Earth.

3.  There are four layers of the atmosphere.

4.  The layer closest to the Earth is the troposphere. We live in the troposphere and breathe in air. Almost all weather happens in this layer.

5.  Some airplanes that travel long distances fly in the stratosphere, above the weather.

6.  The mesosphere is the coldest layer of the atmosphere.

7.  The thermosphere is the hot, outermost layer of air.

8.  An air mass is a large body of air that has temperature and moisture similar to that of the area over which it formed. Ex: A warm, moist air mass is most likely to form over the Gulf of Mexico.

9.  Humidity is the amount of water vapor in the air.

10.  A front is the area where two air masses meet and where weather happens.

11.  A cold front forms when a cold air mass catches up with a warm air mass.

12.  A warm front forms when a warm air mass catches up to a cold air mass.

13.  A cold front is represented with a line with triangles.

14.  A warm front is represented with half circles.

15.  Cirrus clouds are a wispy white cloudS at a high altitude.

16.  Cumulus clouds are dense, white, fluffy, puffy cotton-ball clouds.

17.  Cumulonimbus clouds are towering dark clouds. If you see them it will probably rain soon.

18.  Stratus clouds form a low layer of dark gray. You see these clouds on a gray cloudy day.

19.  Air pressure(the weight) is measured with an instrument called a barometer.

20.  A thermometer measures the temperature of air.

21.  An anemometer measure wind speed.

22.  A wind vane or wind sock measures wind direction.

23.  The water cycle is the constant recycling of water from Earth’s surface to the atmosphere and back to the Earth’s surface again.

24.  Evaporation is the process in which liquid changes into a gas.

25.  Condensation is the process in which a gas changes to a liquid.

26.  Precipitation is rain, snow, sleet, or hail that falls from the clouds. Precipitation forms when water droplets get too large to stay in the air/clouds.