Guided Notes on the State of the Atmosphere

Chapter 11, Section 2

1. Temperature is a measurement of how rapidly or slowly molecules move around.

2. Heat is the transfer of energy that occurs because of a difference in temperature between substances.

3. Heat is the transfer of energy that fuels atmospheric processes while temperature is used to measure and interpret that energy.

4. The dew point is the temperature to which air must be cooled in order to reach saturation, which is the point at which the air holds as much water vapor as it possibly can. Until air is saturated, condensation cannot occur.

5. In the atmosphere, temperature is directly proportional to pressure. The relationship between temperature and density is inversely proportional. Temperature varies with changes in both pressure and density. The ratio of pressure to density decreases with increasing altitude.

6. A temperature inversion is an increase in temperature with height in an atmospheric layer. This can involve the rapid cooling of land on a cold, clear winter night when the wind is calm. Temperature inversions can worsen air pollution by acting as a lid to trap pollution under the inversion layer.

7. In the lower atmosphere, air generally moves from areas of high density to areas of low density. The air moves in response to density imbalances created by the unequal heating of the Earth. Wind can be thought of as air moving from an area of high pressure to one of low pressure.

8. The amount of water vapor in the air is referred to as humidity. The ratio of water vapor in the air relative to how much water vapor that the air is capable of holding is called relative humidity.

9. Relative humidity varies with temperature because warm air is capable of holding more moisture than cool air. Relative humidity is expressed as a percentage. If a volume of air is holding the maximum amount of water vapor, then its relative humidity is 100%.