Water in the Atmosphere

1. Water in the Atmosphere

2. What do you observe from the glass/water/ice demo. Why do you see this? Explanation: water in the atmosphere video

3. Water Cycle -The continuous movement of water between the atmosphere and Earth’ssurface. takes about 9 days

4. Humidity • A measure of the amount of water vapor in the air. • Warm air can hold more water vapor than cool air.

5. Relative Humidity • The percentage of water vapor that is in the air compared to the maximum amount of water vapor the air can hold. • Depends on temperature • Higher % results in precipitation • Demo or relative humidity demo

6. Psychrometer • Used to measure relative humidity • Has a wet-bulb thermometer and a dry-bulb thermometer. • The wet-bulb thermometer is cooled by evaporation, so the reading drops below that of the dry-bulb thermometer. • Analyze data on p.302

7. How Does Fog/ Cloud Form? • Condensation: molecules of water vapor in the air become liquid water (remember the FQ video) • Two conditions are required for condensation: cooling of the air below dew point and the presence of particles in the air. • hot water fog and fog in a bottle

8. Dew Point • The temperature at which condensation begins. • saturation point • tomorrow’s lab

9. Types of Clouds Classified by: • shape • altitude • precipitation NASA cloud video

10. Types of Clouds • Cirrus ( means a curl of hair) • Cumulus ( means heap or mass) • Stratus ( spread out, wispy)

11. Prefix • Nimbus-/Nimbo- means the cloud produces rain or snow ex: Nimbostratus, Cumulonimbus • Alto- means medium-altitude cloudex: Altostratus, altocumulus • Cirro- means high-altitude cloudex: Cirrocumulus