chapter 4 water in the atmosphere Flashcards
radiation fog
results when the ground radiates heat away at night, cooling air above it to the dew point
advection fog
results from moist air moving over cold surface that lowers its temperature to the dew point.
what is seen in winnipeg
condensation nuclei
small particles, .2 micrometers in diameter that provide a surface on which water vapor can condense
collision and coalescence
the process by which cloud droplets merge to make rain drops
collision and coalescence occurs ar
-15 degrees C and warmer in clouds
ice crystal process
forms snow in clouds in which the temperature is 0 or below
snow can form through deposition or contact freezing
which process occurs in warm clouds and what is the temperature
collision and coalescence process
above 0 degrees C
which process occurs in cold clouds and what is the temperature
ice crystal process
below 0 degrees C
with the exception of ___ all types of precipitation are produced through the collision and coalescence process or the ice crystal process
hail
______ _____ of the atmosphere determines which form or precipitation occurs
temperature profile
hail
hard round pellets of ice 5 mm or more in diameter
hail forms in _____ clouds
cumulonimbus
graupel
small pieces of ice before turning into hailstones
evaporation
change in the state of water from a liquid to a gas
transpiration
plants change liquid water into water vapour by breathing it out the pores on their leaves during photosynthesis
condensation
change in the state of water from a gas to a liquid
sublimation
ice shifts directly to water vapour
deposition
water vapour forms directly into ice
precipitation
solid or liquid water that falls from clouds to the ground
clouds
suspended microscopic water droplets and ice crystals that are visible only when they are grouped together in very large numbers
hydrologic cycle
the circulation of water within the atmosphere, biosphere, lithosphere, and hydorsphere
evapotranspiration
the source of all water vapour in the atmosphere
latent heat
the energy that is absorbed or released during a state change, such as evaporation or condensation
evaporation ____ the environment and condensation ____ the environment.
cools
warms
humidity
the water vapour content of the air
net condensation
occurs when condensation exceeds evaporation, resulting in saturation of the air
saturation
the point at which water vapour content is equal to water vapour capacity
net evaporation
occurs when evaporation exceeds condensation
vapour pressure
the portion of air pressure exerted exclusively by molecules of water vapour
specific humidity
water vapour content of the atmosphere, expressed in grams of water per kg of air
relative humidity
ratio of water vapour content to water vapour capacity, expressed as a percent
temperature and RH are ___ related.
inversely
dew point
temperature at which air becomes saturated
frost point
when the dew point is at or below freezing, deposition forms crystals of ice called frost
dew point depression
the difference between the air temperature and the dew point temperature
air parcel
a body of air with uniform humidity and temperature
adiabatic cooling vs adiabatic warming
cooling- cooling of an air parcel through expansion
warming- warming of an air parcel through compression
dry adiabatic rate
rateof temperature change in an unsaturated parcel of air, water vapour in it but you cannot feel it
environmental lapse rate
decrease in air temperature outside the air parcel as altitude increases
moist adiabatic rate
rate of cooling in a saturated air parcel
unstable vs stable atmosphere
unstable- air parcels that are warmer and less dense that the surrounding air and rise on their own
stable- the interior of air parcels is cooler and denser than the surrounding air
rain shadow
the dry environment on the leeward side of a mountain range, caused by adiabatic warming
convective uplift
rising of an air parcel that is warmer and less dense than the surrounding air
orographic uplift
rising of air over mountains
frontal uplift
rising of warm air masses where they meet relatively cold air masses
convergent uplift
rising of air as a result of converging airflow
intertropical convergence zone
converging and rising air strengthens convective uplift and thunderstorms, convective and convergent uplift blend together into a single process
nimbostratus
rain producing low level sheets of clouds
cumulonimbus
cloud that extends high into the atmosphere and is capable of strong vertical development and severe weather
cirrus
high clouds with a feathery appearance that are composed of ice crystals
stratus
clouds that are low flat sheets
nimbostratus
rain producing sheets of clouds
cumulus
bunched clouds with a flat base and billowy upper portions that often rise high into the troposphere
cumulonimbus
heaped up rain and hail clouds capabe of strong vertical development that may produce severe weather
