exam 3 Flashcards
(106 cards)
the weight of air above a given surface
air pressure
as you climb in elevation, there are fewer air molecules above you, therefore , air pressure always ______ with height
decreses
two identical columns of air (fixed width):
if we move air into the column with no temperature change…
surface pressure would increase
two identical columns of air (fixed width):
if we move air out of the column with no temperature change…
surface pressure would decrease
two identical columns of air (fixed width with same air pressure):
if we warm one column…
the molecules move faster and spread farther apart, the air becomes less dense and the column expands in height
two identical columns of air (fixed width with same air pressure):
if we cool one column…
the molecules move more slowly and crowd closer together, the air becomes more dense and the column shrinks in height
it takes a ____ (shorter/taller) column of cold, dense air to exert (less, more, same) surface pressure as taller column of warm, less dense air
shorter, same
atmospheric pressure decreases more rapidly with elevation in a ______ (warm/cold) column of air
cold
true/false: high pressure is always cold
false ; high pressure is not always hot or cold, it depends on where it is in the atmosphere
atmospheric pressure decreases more slowly with elevation in a _____ (warm/cold) column of air
warm
warmer air aloft is normally associated with ________ (higher/lower) atmospheric pressure aloft
higher (resulting in a more stable atmosphere)
colder air aloft is normally associated with _________ (higher/lower) atmospheric pressure aloft
lower (resulting in a more unstable atmosphere)
unequal heating of the Earth’s surface causes…
the wind to blow (lack of equilibrium)
how do we measure air pressure
barometers (mercurial vs. aneroid)
corrections must be made for what factors when measuring air pressure
- temperature
- instrument
- gravity
- sea level
atmospheric pressure decreases, on average, ____ inch of ______ for each ______ foot rise in altitude
one ; mercury ; 1000
what is the standard surface atmospheric pressure
- 2 mb (milibars)
- 7 lbs/inch
- 92 “ mercury
high pressure is also referred to as…
“anticyclone”
(rising/sinking) air is more stable ; is this more associated with high or low pressure?
sinking ; high pressure
a “mountain” of air above a given location
high pressure
a “valley” of air above a given location
low pressure
low pressure is also referred to as…
“cyclone”
(rising/sinking) air is more unstable ; is this more associated with high or low pressure?
rising ; low pressure
storminess is generally brought by (high/low) pressure
low pressure (rising air)