Ch. 17

Calculate the percent relative humidity given the absolute humidity and the maximum moisture content.

% Relative Humidity = % R.H. = actual moisture content/maximum moisture capacity X 100%

Name and describe the meanings of the four basic cloud root names.

1. Cirrus - high, white, thin, wispy, feathery 2. Cumulus - billowy, rounded forms, may have a flat base, cauliflower structure 3. Stratus - sheets or layers, cover much of the sky 4. Nimbus - produces precipitation

Name and briefly describe four ways in which air may be lifted, cooled below the dew point, and form a cloud.

1. Convergence - air from diff regions flows toward the same area 2. Frontal Wedging - warmer air is forced over colder air 3. Orographic Lifting - air is forced over mountains 4. Local Convective Lifting - localized warmer pockets of air rise because of unequal surface heating

What is the difference between absolute humidity and relative humidity?

Humidity is the amount of water vapor in the air. Absolute humidity is the weight of water vapor per ft^3 of air.

What time of the day are we most likely to have the highest percent relative humidity? The lowest?

Sunrise, late afternoon

What is meant by the dew point temperature?

The temperature to which air must be cooled to reach saturation...temperature at which % R.H. = 100%

Name some examples of condensation nuclei and briefly describe their role in cloud and rain formation.

occurs when water vapor in the air changes to liquid, produces dew, fog, clouds