Cloud Formation and Precipitation Flashcards
what is the adiabatic principle?
as a gas expands it cools down, as it is compressed it warms up
as a gas ________ it cools down
expands
what happens when a gas expands?
it cools down.
as a gas ________ it warms up
compresses
when a gas compresses it…
warms up
the temperature change of gas is based solely on __________
increase or drecrease of pressure
in the atmosphere as you increase in _________ the ________ decrease
altitude, pressure
what happens when you increase in altitude?
pressure drops
why doe pressure drop when you increase in altitude?
you have less atmosphere above you
as air rises it….
expands and cools down
as air sinks it..
is compressed and warms
what is the dry adiabatic rate?
as dry air raises it cools at a particular rate, 10 celsius per 1000m
what is the wet adiabatic rate?
if you have a wetter parcel of air and it rises it cools down at a slower rate. 5 celsius per 1000m
why does wet air cool slower?
because all of the moisture in that air is condensing as it cools down and the process of condensation release heat
the wet adiabatic rate increases….
condensation
an increase of condensation in the atmosphere causes what to form?
clouds
_____ air has to rise higher then ______ air in order for clouds to form
dry, wet
clouds form when water vapor ______ in rising air parcels
condenses
condensation requires…
the presence of particles (like dust) suspended int he air
what are the presence of parties suspended in the air called?
condensation nuclei
what do condensation nuclei allow the air to do?
glom on to nuclei and form coherent rain or water droplets.
what are the four families clouds are grouped into?
high, middle, low, and clouds with vertical development
what are the two classes of clouds?
stratiform, cumuliform
what are the two classes of clouds based on…
their shape
stratiform are ______ clouds
layered
cumuliform are _________ clouds
globular
moisture-laden clouds release moisture as…
precipitation
in order to form precipitation there must be something that..
causes air to rise int he atmosphere so that it cools down enough to reach its dew point
what are the four ways that air moves upward to form precipitation
- orographic precipitation
- convectional precipitation
- cyclonic precipitation
- convergence
how does orographic precipitation occur?
when air is forced to move up because of the presence of a mountain
As moist air _______ it expands and _______
rises, cools
once moist air hits its dew point what happens?
condensation occurs, and clouds starts to form
when air is forced to move up because of the presence of a _______ it is called orographic precipitation
mountain
how does convection precipitation occur?
forms when warm, moist air heats up near a hot surface, as the air rises it starts to cool back down, and starts to form clouds
convectional precipitation and orographic precipitation are methods that cause air to ______ in the atmosphere
rise
where do thunderstorms form?
in extremely unstable air conditions, where the environmental lapse rate exceeds wet adiabatic rates,
air where thunderstorms form is __________
humid
when very humid air rises it remains ______ than the surrounding air
warmer
what kind of clouds to thunderstorms form in?
vertically developing clouds
