39 terms

Earth Science CH. 23

latent heat
the heat energy that is absorbed or released by a substance during a phase change
the process in which a solid changes directly into a gas (the term is sometimes also used for the reverse process)
dew point
at a 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 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
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
water vapor that has condensed very near the surface of earth because air close to the ground has cooled
any form of water that falls to Earth's surfae from the clouds; includes rain, snow, sleet, and hail
the formation of a large droplet by the combination of smaller droplets
a condition in which a substance is colled below its freezing point, condensation point, or sublimation point without going through a change of state
cloud seeding
the process of introducing freezing nuclei or condensation nucei into a cloud in order to cause rain fall
state of matter
water vapor
water as a gas
process in which collisions between molicules due to an addition in energy (heat) cause the molecules to move so rapidly that the fastest moving molecules escape from the liquid to form invisible water vapor
process in which energy is released to the surrounding air and the molecules move closer together; water vapor changes back into a liquid
water vapor in the atmosphere controlled by rates of condensation and evaporation
when the rate of evaporation and the rate of condensation are in equilibrium
resulting form of condensation when temperature reaches the dew point
forms when the dew point falls below the freezing temperature of water, and the water vapor cahnges directly into solid ice crystals
adiabatic lapse rate
the rate at which the temperature of a parcel of air changes as the air rises or sinks
condensation level
the altitude at which net condensation begins; marked by base of clouds
radiation fog
forms from the nighly cooling of Earth; the layer of air in contact with the ground becomes chilled to below the dew point, and the water vapor in that layer condenses into droplets (results from loss of heat by radiation)
advection fog
forms when warm, moist air moves across a cold surface (common along coasts)
upslope fog
froms by the lifting and cooling of air as air rises along land slopes
steam fog
shallow layer of fog that forms when cool air moves over an inland warm body of water (such as a river)
freezing nuclei
solid particles that are suspended in the air and that have structures similar to the crystal structure of ice
liquid precipitation
rain consisting of drops smaller than 0.5mm in diameter
precipitation consisting of ice particles
clear ice pellets formed when rain falls through a layer of freezing air
glaze ice
a think layer of ice on a surface
ice storm
the condition which produces glaze ice
solid precipitation in the form of lumps of ice