humidity quiz Flashcards
(23 cards)
what is humidity?
the quantity of water vapor in the air
is water constant through space & time (the hydrologic cycle)?
no
what percent of water vapor in earth’s atmosphere comes from the ocean?
85%
what is absolute humidity?
mass of water vapor per volume of air
(g/m^3 = volume)
what is specific humidity?
mass of water vapor / mass of (all) air
what is mixing ratio?
mass of water vapor / mass of dry air
what is vapor pressure?
the pressure exerted by water vapor molecules in an air parcel
what percent is vapor pressure of the total air pressure?
1% or so
what three phases of water can the atmosphere hold? examples of each?
solid (ice crystals, snow, hail)
liquid (rain drops, cloud drops)
gas (water vapor)
what phase changes release latent heat?
condensation
freezing
deposition (ice –> vapor or vapor –> ice)
what phase changes cool environment?
evaporation
melting
sublimation
can warm air or cold air hold more moisture?
warm air
what is saturation vapor pressure?
vapor pressure at which an air parcel is saturated
(when condensation = evaporation)
what is relative humidity?
(actual water vapor/saturation water vapor) x 100%
what is the temperature at which saturation occurs?
dew point
what indicates how close to saturation?
relative humidity (RH)
what indicates amount of water vapor?
dew point
high relative humidity equates to…
less evaporative cooling
which is lighter, humid air or dry air?
humid air
why is humid air lighter than dry air?
due to molecular weight of water compared to nitrogen
why does dew form?
when they cool to the dew point temperature
what is frozen dew?
vapor that first condenses and then freezes
what does condensation in the atmosphere require?
a surface
