Atmosphere and Weather Flashcards
What is the atmosphere?
volume of gases, water vapor, and airborne particles enveloping Earth
Is the atmosphere stable or unstable and why?
Unstable because heated from below
Where is most of the mass of the atmosphere (what level)?
Troposphere
What are the 4 levels of the atmpsphere?
troposphere, stratosphere, mesosphere, thermosphere
What are the 3 zones in between the levels of the atmosphere?
tropopause, stratopause, mesopause
What is weather?
state of atmosphere at a specific time
What is climate?
long-term statistical sum of weather in an area
What are the 2 main components of the air?
Nitrogen (78%), Oxygen (21%)
Why does warm air rise and cool air sink?
Warm air is less dense
Humid air is ____ dense than dry air
less, it sinks
Why is air less dense at higher altitudes?
There is less pressure the higher you go so air is less dense
Air ____ as it expands and ____ as it is compressed
cools, warms
What happens if condensed water vapor coalesce to a large enough mass in the sky?
precipitation
What is the difference between shortwave and longwave radiation?
shortwave comes from the sun, longwave goes from earth out
What is the global heat budget?
The earth is in heat equilibrium because the amount taken in is equal to the amount leaving
Why does shortwave radiation vary with latitude?
The tilt of the earth’s axis spreads the light over the poles and there is a direct hit with little spreading by the equator
What causes convection currents?
rising warm air and descending cool air circulates
What is the coriolis effect?
The deflection of objects (or air currents) to one side moving from the equator either north or south
cannonball example
Which direction is the curve in the different hemispheres?
North: counterclockwise
South: clockwise
What is the ITCZ
InterTropical Convergence Zone
the area where the northeast and the southeast trade winds converge
What are Hadley, Ferrel, and Arctic cells?
areas of convection currents. each hemisphere has one of each
hadley: 0-30
ferrel 30-60
arctic: top and bottom of the earth
What are the doldrums?
low pressure winds at equator
What are the horse latitudes?
high pressure at 30°
What are the strong and dependable winds that are horizontal air movement between the cells?
trade winds; 15°, westerlies; 45°
What is the monsoon?
pattern of wind circulation that changes with the season
wet summers, dry winters
What is the cause of monsoons?
in spring, land heats more quickly than ocean
air above land rises, cool air from ocean flows toward low pressure created by rising air over land
moist cool air heats and rises, vapor condenses, rains
What are sea breezes/land breezes and why are they caused?
land heats, air rises creating low pressure zone
breeze from the ocean blows toward low pressure zone
sea breeze
Land breeze occurs at night
What is a cyclone?
large rotating masses of low-pressure air in which winds converge and ascend
What is an air mass?
large body of air with nearly uniform temperature,
humidity (density) throughout
What are storms?
regional atmospheric disturbances characterized by strong winds and (potentially) precipitation
What is a front?
the boundary between air masses
can be cold or warm
What are extratropical cyclones?
snow storm
form between the Ferrel cell and the Polar cell (polar front)
occur in winter when temperature and density differences between air masses is greatest
What are tropical cyclones?
hurricanes or typhoons if winds 74+ mph
masses of warm, humid, rotating air
What is a storm surge?
the mass of water driven by the storm
low atmospheric pressure at storm center (the eye) produces a dome of water
water height increases when waves and winds ramp the water mass on shore
