Test 4 Flashcards
Types of Humidity
Absolute - actual amount of water vapor in a parcel of air
Relative - actual amount of water vapor in a parcel of air divided by the amount of water vapor the air can absorb
Capacity
Determined by temperature
Higher the temperature higher the capacity
Dew point
Temperature at which condensation occurs
If dew temp. is greater than 32 degrees and temp is passed, condensation of dew occurs
If dew temp. is less than 32 degrees and temp is passed, depositions of frost occurs
Adiabatic temperature changes
As air expands, it cools
As air is compressed, it heats
Types of clouds
Cirrus High altitude ( 6000 or greater Thin, veil like Stratus Low to mid alt Thick, blanket like Cumulus Low to mid alt Puffy, pillow like Cumulonimbus Storm Warm air rises rapidly
Rising air
Convective lifting - heated air rises
Orographic lifting - air encounters a physical barrier
Frontal lifting - cool air forces warm air to rise
Convergence - two air masses collide
Air pressure
Weight of overlying air at any given location
Wind
Horizontal movement of air
Standard atmospheric pressure at sea level = 1013.2 millibars
Factors controlling wind
Pressure Gradient Force difference in air press, generates wind Coriolis effect Affects wind direction, not speed, greatest at poles, faster wind=greater deflection Friction Resistance to flow Not significant above 700 meters
Isobar
Lines that connect places of equal air pressure
Closer = faster winds
Farther = slower winds
Cyclone
Low pressure system
Winds blow counter clock wise
Winds converge and rise
Associated with clouds and precipitation
Anti cyclone
High pressure system
Winds blow clock wise
Winds descend and diverge
Clear skies
Global wind patters
Vertical Equatorial low - air rises Sub tropical high - air falls Sub polar low - air rises Horizontal Trade winds - NE to SW Westerlies - SW to NE Polar easterlies - north to SW
Classifying air masses
Tropical (t) - warm
Polar (p) - cold
Marine (m) - humid
Continental (c) - dry
Tornado
Rotating column of air
