Meteorology Flashcards
what is Meteorology?
the study of Earth’s heat balance
what are the 4 factors that affect weather/climate?
temperature (most important)
moisture
air pressure
wind
what causes temperature?
the amount of solar radiation
what are the 2 factors that affect the amount of solar radiation?
Intensity: angle of rays strike surface
Duration: length of daylight
what is albedo?
the radiation that is reflected by a surface
how much of the Earth is albedo?
30%
what is air pressure?
force air exerts on everything it touches
what are the 3 things that air pressure depend on?
number of air molecules
amount of space
how fast molecules move
what is an air mass?
large body of air that takes on the characteristics of the area over which it forms
what are the 2 characteristics of an air mass?
average temperature
average humidity
the ability of air to ___ ____means that the air mass is stable
resist rising
the rate that the air mass expands and cools depends on what 3 factors?
temp of surface below the air
temp of surrounding air
temp of air mass itself
cool land, warm air is an example of a(n) ____ air mass
stable
continental air masses (c) are…
dry
maritime (bodies of water)(m) air masses are…
humid
polar (P) air masses are…
cold
what is an mP air mass?
humid + cold
what is an mT air mass?
humid + tropical
what is a cP air mass?
dry + cold (continental polar)
what does a barometer measure?
the weight of the air
millibars are…
measure of actual force of the air
what happens is a low pressure system?
air rises
must be replaced from outside so air flows in toward center
counterclockwise flow (think removing a screw)
what happens in high pressure systems?
air sinks
spreads away from center when reaches Earth’s surface
deflect to right in northern hemisphere due to Coriolis
think screwing a screw in
what would you expect the air pressure to do is there is a storm approaching?
rapidly falling air pressure
what would you expect the air pressure to do in fair weather?
rapidly rising air pressure
what are winds?
horizontal movement of air
flows from high to low pressure
what do global wind systems do?
they move air masses to balance out uneven heating of Earth
there are 3 distinct zones in each hemisphere. what are they? what are they acted upon by?
trade winds
prevailing westerlies
polar easterlies
-they are acted upon by the Coriolis effect
what happens with the air during trade winds
the air sinks, moves toward equator
at equator, warms, rises, then moves to 30 degrees
what happens at an inter-tropical convergence zone?
2 air masses meet and then get forced up then it rains
creates rain forests
what are jet streams?
narrow bands of westerly winds, fast, high altitude,
caused by large temperature and pressure gradients
what act as railroad tracks for large scale weather systems?
jet streams
what is a front?
narrow region separating 2 air masses of different densities
in a front, what are the density differences caused by?
temperature
pressure
humidity
what shows a cold front on a weather map? warm front?
cold= solid blue line with triangles pointing IN direction of motion warm= solid red line with semi-circles pointing IN direction of motion
what happens when a cold front and warm air mass meet?
cold air displaces warm air
warm air rises quickly (steep front)
cools
condenses
when a cold front and warm air mass meet, what does it cause?
clouds, thunderstorms, showers
what shows a stationary front on a weather map?
triangles and semi circles on opposite sides of line
what happens in a stationary front?
the 2 air masses meet and stall
masses are modified enough to be very similar to each other
temp and pressure gradients= very small
in a stationary front, the weather ends up being similar to a ______ front
warm
what represents an occluded front on weather map?
alternating purple triangles and semi-circles pointing in direction of motion
what happens in an occluded front
warm air squeezed between 2 cold fronts
precipitation on both sides
mid latitude cyclones are types of ___ pressure systems
low
where do mid latitude cyclones form?
along stationary fronts
