Chapter 2 Test: Air Pressure and Air Circulation
ITCZ
big, long line of thunderstorm
jet stream
blow from west to east but the flow can shift to north south
subtropic high
cause of many major deserts
friction
causes air to blow across isobars
Global Circulations
causes some places to have semi-permanent lows and highs
weather
changes in the air pressure causes changes to the ___
Santa Anna Winds
chinook style wind - hot, dry, dust bearing winds invade California most often in autumn and bring temps that often exceed 90 degrees
higher
cold air = (higher/lower) pressure
east
cold current: (east/west) side of basin
polar high
cold, dense air sinks - air diverges toward lower latitudes
higher
cold, dry air mass will produce (higher/lower) surface pressure than a warm, humid air mass
eastward
commercial aircraft use jet streams when going (eastward/westward)
low
cyclone: (high/low) pressure
synoptic
cyclones and anticyclones are examples
increase
decrease in pressure with an (increase/decrease) in altitude
coriolis force
deflection of winds caused by rotation of the earth
Coriolis effect
deflection of winds caused by the rotation of the earth
density = mass / volume
density equation
lower
denver has a (higher/lower) pressure than Miami
gradient
difference in pressure over a distance
mountain and valley breeze
during the day, air along mountain slopes is heated more intensely than air in the bottom of a valley - this leads to warm air rising up along the mountain slop and create a valley breeze
same
equatorial low and ITCZ are the ___ thing
microscale
events that have a life span from a few seconds to minutes (wind gusts)
Torricelli's Barometer
found out it was not a vacuum but atmospheric pressure
warm
gas molecules in (warm/cold) air have abundant kinetic energy, and they are more widely spaced (less dense)
temperature imbalance
global circulations are driven by ___
geostropic winds
gradient of pressure and coriolis force coming in to balance
high
gradual pressure gradient = (high/low) pressure system
friction
greatest at earth's surface - different over land and water
strengthened
gulf stream is ___ by prevailing winds
pressure gradient
high pressure air going to low pressure areas
horse latitudes
horse latitudes
Caribbean
in the north atlantic, the equatorial current is deflected northward through the...
macroscale
includes large planetary flow extended around the entire glove and can remain unchanged for weeks at a time (ex: trade winds)
isobar
indicate changes in pressure on a mpa
100kt + wind speed / 10-12km in altitude
jet stream
steep pressure / temp gradient
jet stream happens when there is>>>
mesoscale event
land and sea breezes fall into this category
thermal equator
latitude where noontime sun is directly overhead
isobars
lines connecting equal points of pressure
close
low pressure means isobars are (close/far)
far
low pressure means isobars are (close/far)
single cell model
model invented by George Hadley in 1735 - he was aware that solar energy drives the winds - he proposed the the large temp contrast between the poles and the equator creates one large convective cell in each hemisphere - doesn't take into consideration the earth rotation on its axis
lower
moist air = (higher/lower) pressure
lighter
moist air is (lighter/heavier) than dry air
jet stream
narrow ribbon of high-speed winds that meander for thousands of kilometers
windspeed
pressure gradient force is directly related to __
differ
pressures ___ from place to place
Foehn winds
warm, dry winds sometimes move down the alps
chinook winds
warm, dry winds sometimes move down the east slope of the Rockies
clear skies
weather associated with high pressure...
storms
weather associated with low pressure...
anticyclone
weather system with high atmospheric pressure at center
rises
warm air = volume (rises/falls)
lower
warm ari = (higher/lower) pressure
west
warm current: (east/west) side of basin
loads
(loads/no) precipitation at equator because of ITCZ
right
Coriolis Force makes northern hemisphere go (right/left)
left
Coriolis Force makes the southern hemisphere go (right/left)
subsiding air
___ causes clear skies and warm temps
temp and water vapor content
____ and ___ influence air pressure
30 degrees NS
____ high pressure at subtropical height (explains distribution of precipitation)
synoptic scale
a somewhat smaller macro scale circulation
prevailing winds
a wind from the direction that is predominant at a particular place or season
out
air moves (out/in) from high pressure areas
in
air moves (out/in) low pressure areas
high / low
air moves from (high/low) pressure to (high/low) pressure
proportional
air pressure is ___ to density
high
anticyclone: (high/low) pressure
high
areas of (high/low) pressure are formed when air is sinking back down, and so pushing down harder on the surface
ITCZ
around the equator =
pressure
as the density of a column of air increases, so does the ___ it exerts on the surface
mesoscale
associated with local winds that generally last from minutes to hours (tornadoes)
10mb / 100m
average rate of change used to adjust pressures for all locations to sea-level pressure values
falls
volume increases = density (rises/falls)
subpolar low
responsive for much of the stormy weather in the middle latitudes, particularly in the winter
thunderstorm
rising air promotes ___ development
subtropical high
sinking air in the subtropics piles up and must diverge
microscale events
smallest scale of air motion - chaotic winds that normally last for a few seconds and at most most minutes (ex: gusts, dust devils)
trade winds
some air flows northward, some flows southward to create ___
1013.25mb = 1013.25hPa = 29.92in
standard sea level pressure
low
steep pressure gradient = (high/low) pressure system
pressure gradient force
system want to return to equilibrium - thus air moves from high pressure to low pressure
land and sea breeze
the daily temp contrast between land and the sea and the pressure pattern generates this
mountainous regions
the fact that density decreases with altitude is why the term "thin air" is normally associated with ___
mesoscale events
these systems are always embedded within and his move as part of the larger macro scale circulation
air moves from high pressure to low pressure
this is how winds are formed
intertropical convergence zone
trade wind convergence
Coriolis Force
turning of an object's trajectory due to earth's rotation
single cell model and three cell model
two general circulation models...
millibar
unit of measure for atmospheric pressure
minibars (mb), inches of mercury (in) and hectopascal (hPa)
units of measure for comparing atmospheric pressures
lower
when air rises, it leaves behind an area of (higher/lower) pressure, because the upward-moving air is not pressing down so hard on the surface
thin ribbons of fast moving air occur where the warm subtropical and cool polar air masses meet
where the jet stream occurs
convergence
wind blowing into a region
divergence
wind blowing out of a region
pressure gradient force, Coriolis force, and friction
wind is controlled by...
convergence
winds blowing into a region - air piles up, must begin to flow upward
divergence
winds blowing out of a region - associated with a decrease in pressure
perpendicular
winds move ___ to isobars
