Water in the Atmosphere

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

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

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

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

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

How Does Fog/ Cloud Form? Condensation: molecules of water vapor in the air become liquid water (remember the FQ video) 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. 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 hot water fog and fog in a bottle hot water fog in a bottle hot water fog in a bottle

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

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

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

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