chapter 5 atmospheric circulation and wind systems Flashcards
barometer
an instrument used to measure air pressure
thermal vs dynamic pressure
thermal- results from changes in temperature
dynamic- caused by air movement
three forces that control wind speed and direction near earths surface
- pressure gradient force
- coriolis force
- friction force
pressure gradient force
the resulting force from changes in barometric pressure across earths surface
isobar
a line drawn on a map connecting points of equal pressure
pressure gradient runs ______ to isobars
perpendicular
coriolis effect
perceived deflection of moving objects in relation to earths surface
coriolis effect: in the northern hemisphere objects veer to the ___. in the southern hemisphere objects veer to the ___.
right
left
friction layer
the area of the atmosphere where wind is slowed by the friction with earths surface
geostrophic winds
fast, high altutude winds that are strongly deflected by the coriolis effect
anemeter
measures wind based on the speed of propeller rotation when exposed to the wind
aerovane
a wind vane and anemometer combined as a single instrument
three ways to portray wind on a map
wind barb
wind vectors
streamlines
cyclone vs anticyclone
cyclone- a region of low pressure with counterclockwise circulation in the northern hemisphere
anticyclone- a region of high pressure with clockwise rotation in the northern hemisphere
ITCZ
a discontinuous band of thermal low pressure and thunderstorms that encircles the planet in the tropics
subtropical high
a discontinuous belt of dynamic high pressure and aridity made up of anticyclones
subpolar low
a discontinuous belt of dynamic low pressure
polar high
an area of cold, dense air at each pole that forms a zone of thermal high pressure
trade winds
easterly surface wins found from the ITCZ to the subtropical high, between 0 and 30 degrees N/S
doldrums
a low wind region near the equator associated with the ITCZ where the trade winds meets
horse latitude
a low wind region centered on 30 degrees n/s
westerlies
surface winds that come from the west and are found in both hemispheres between the subpolar low and the subtropical high
polar easterlies
cold, dry wins originating near both poles and flowing south and east
polar jet stream
a fast ribbon of air that occurs on the boundary of the polar cell and meanders between 45-70 degrees n/s
rossby waves
large n/s undulations in upper level westerlies
mountain breeze
air flow from mountain slopes to adjacent valleys
valley breeze
air flow from a valley upslope to higher elevations
sea breeze
local onshore breeze created by heating and development of thermal low pressure over land
land breeze
local offshore breeze by cooling and development of thermal high pressure over land
chinook wind
downslope wind that forms on leeward side of rocky mountains
foehn wind
downslope wind that forms on leeward size of european alps
santa ana winds
dry and warm winds that originate in the great basin and flow offshore i southern california
diablo winds
dry and warm winds that originate in the great basin and flow through the central valley in northern california
katabatic wind
wind that forms mainly over ice sheets or glaciers when intensely cold, dense, and heavy air spills downslope by the force of gravity
monsoon
a seasonal reversal of winds
el nino
a periodic shift in the state of earths climate caused by the temporary slackening and reversing of the pacific equatorial trade winds and increased surface temperatures in the seas near peru
la nina
often follows el nino and creates enhanced normal meteorological conditions for affected areas
wind energy
electricity that is derived from wind turbines
three major challenges for wind power
- geography
- meeting peak demand
- environmental impacts
