Chapter 20 Flashcards
sublimation
the process in which a solid changes directly into a gas (the term is
sometimes also used for the reverse process)
dew point
at constant pressure and water vapor content, the temperature at which the rate of condensation equals the rate of evaporation
absolute humidity
the mass of water vapor per unit volume of air that contains the water vapor, usually expressed as grams of water vapor per cubic meter of air
relative humidity
the ratio of the amount of water vapor in the air to the amount of water vapor needed to reach saturation at a given temperature
cloud
a collection of small water droplets or ice crystals suspended in the air, which forms when the air is cooled and condensation occurs
condensation nucleus
a solid particle in the atmosphere that provides the surface on which
water vapor condenses
adiabatic cooling
the process by which the temperature of an air mass decreases as the air mass rises and expands
advective cooling
the process by which the temperature of an air mass decreases as the air mass moves over a cold surface
stratus cloud
a gray cloud that has a flat, uniform base and that commonly forms at very low altitudes
cumulus cloud
a low-level, billowy cloud that commonly has a top that resembles cotton balls and a dark bottom
cirrus cloud
a feathery cloud that is composed of ice crystals and that has the highest altitude of any cloud in the sky
fog
water vapor that has condensed very near the surface of Earth because air close to the ground has cooled
latent heat
the heat energy that is absorbed or released by a substance during a phase change
