| A | B |
|---|
| compass | instrument used to determine the direction FROM which the wind is coming |
| anemometer | instrument used to measure wind speed |
| thermometer | instrument used to measure temperature - it uses the Celsius (C) or Fahrenheit (F) |
| hygrometer | instrument used to measure relative humidity - the amount of water vapor in the the air |
| barometer | instrument used to measure air pressure - it is measured in mb(millibars) |
| atmosphere | the layer of gases that surround a planet or star |
| air | on Earth,what we call our atmosphere - it is mostly made up of Nitrogen (78%) and Oxygen (21%) |
| permanent gases | gases in our atmosphere that remain constant - the amount of nitrogen and oxygen in the atmosphere stays constant |
| variable gases | the amount of gases in the atmosphere that change in response to activities in the environment |
| ozone | a form of oxygen that forms a thin layer in the stratosphere that absorbs deadly ultraviolet radiation from the Sun |
| troposphere | the layer of air we live in - weather factors occur in this layer |
| weather factors | temperature, humidity, pressure, and wind |
| stratosphere | the layer of atmosphere above the troposhpere |
| air pressure/atmospheric pressure | the air that pushes down on the surface of the Earth with a lot of force |
| mesosphere | the layer above the stratosphere |
| ionosphere | the layer within the thermosphere that is known for its chemistry |
| exosphere | the layer in which atoms and molecules escape into space |
| Nor'easter | a storm that moves up the east coast |
| hot air | rises, expands, and then cools |
| weather in the Northern Hemisphere generally moves from | West to East |
| air pressure is read in | millibars |
| high pressure | "happy weather" |
| low pressure | "lousy weather" |
| relative humidity | the amount of water vapor in the air divided by the amount of water vapor for the air to be saturated |
| fronts | narrow zones between two air masses |
| warm air | less dense than cold air |
| cold air | more dense than warm air |
| trough | low pressure that brings cold, cloudy weather |
| ridge | high pressure that brings warm, clear weather |
