1. Weather
Chapter 16 Notes

2. Weather - the condition of the atmosphere at a certain time and place
Weather - the condition of the atmosphere at a certain time and place. It includes temperature, humidity, precipitation, wind, and visibility.

3. The water cycle is the continuous movement of water from sources on Earth's surface -such as lakes, oceans, and plants - into the air, onto and over land, into the ground, and back to the surface. Water in liquid, solid, and gaseous states is constantly being recycled through the water cycle.
(See the diagram on p. 482)
Precipitation - Runoff- Evaporation - Condensation - Clouds form - Precipitation

4. Humidity - amount of water vapor in the air.
Relative humidity - the ratio of the amount of water vapor in the air to the maximum amount of water vapor the air can hold at a specific temperature.
As air gets warmer the amount of water vapor it can hold increases. Cold air holds less water vapor than warm air.
Two factors that affect relative humidity -
1. amount of water vapor
2. temperature

5. psychrometer - an instrument that is used to measure relative humidity
Condensation - the change of state from a gas to a liquid.
Dew point - the temperature at which a gas condenses into a liquid.
Air can become saturated when water vapor is added to the air through evaporation. Air can also become saturated when it cools to its dew point.