Chapter 17

Front 1

evaporation

Back 1

process of converting liquid to gas

Front 2

condensation

Back 2

change of state from gas to liquid

Front 3

melting

Back 3

change of state from solid to liquid

Front 4

freezing

Back 4

change of state from liquid to solid

Front 5

sublimation

Back 5

conversion of a solid directly to a gas without passing through the liquid state

Front 6

deposition

Back 6

water vapor is changed directly to a solid without passing through the liquid state

Front 7

calorie

Back 7

amount of heat needed to raise one gram of water to 1 degree C

Front 8

latent heat

Back 8

energy absorbed or released during a change in state

Front 9

humidity

Back 9

actual moisture content (specific humidity)

Front 10

saturation

Back 10

maximum quantity of water vapor that the air can hold at any given temperature or pressure

Front 11

vapor pressure

Back 11

part of the total atmosphere pressure attributable to water vapor content

Front 12

mixing ratio

Back 12

mass of water vapor in a unit mass of dry air

Front 13

relative humidity

Back 13

ratio of the air's water-vapor content to it's water vapor capacity

Front 14

dew point

Back 14

temperature to which air has to be cooled in order to reach saturation

Front 15

psychrometer

Back 15

two thermometers that is rapidly whirled and with the use of tables yields the relative humidity and dew point

Front 16

hygrometer

Back 16

measure relative humidity

Front 17

condensation nuclei

Back 17

tiny bits of particulate matter that serve as surfaces on which water vapor condenses

Front 18

adiabatic temperature changes

Back 18

cooling or warming of air caused when air is allowed to expand and condense/compressed

Front 19

parcel

Back 19

imaginary volume of air enclosed in a thin elastic cover

Front 20

dry adiabatic rate

Back 20

cooling and warming in unsaturated air

Front 21

wet adiabatic rate

Back 21

temperature change in saturated air . . . rate is variable, but less that the dry adiabatic rate

Front 22

absolute stability

Back 22

air with a lapse rate greater than the dry adiabatic rate

Front 23

conditional instability

Back 23

moist air with a lapse rate between the dry and wet adiabatic rate

Front 24

absolute instability

Back 24

air that has a lapse rate less than the wet adiabatic rate

Front 25

convergence

Back 25

distribution of winds within a given area results in a net horizontal inflow of air into an area

Front 26

orographic lifting

Back 26

mountains acting as barriers to the flow of air . . . forcing air to ascend

Front 27

rain shadow desert

Back 27

dry area on the lee side of a mountain range

Front 28

frontal wedging

Back 28

lifting of air resulting when cool air acts as a barrier over which warmer, lighter air will rise

Front 29

cirrus clouds

Back 29

thin delicate ice-crystal clouds . . . appear as veil-like patches, thin and wispy fibers

Front 30

cumulus clouds

Back 30

billowy individual cloud masses that have flat bottoms

Front 31

stratus clouds

Back 31

sheets or layers that cover most of or all of the sky

Front 32

rain

Back 32

water released by clouds when full of moisture

Front 33

sleet

Back 33

frozen or semi-frozen rain that freezes as it falls

Front 34

snow

Back 34

solid form of precipitation produced by sublimation of water vapor

Front 35

hail

Back 35

spherical ice pellets having concentric layers and formed by the successive freezing of layers of water

Front 36

fog

Back 36

cloud with its base at or very near Earth's surface

Front 37

advection fog

Back 37

formed when warm,moist air is blown over a cool surface

Front 38

radiation fog

Back 38

resulting from radiation heat loss by Earth

Front 39

upslope fog

Back 39

air moves up a slope and cools

Front 40

steam fog

Back 40

appearance of steam produced by evaporation from a warm surface

Front 41

frontal fog

Back 41

rain evaporates when it falls through a layer of cool air

Front 42

precipitation fog

Back 42

rain evaporates as it falls through a layer of cool air