GEO CH 8 Flashcards
Weather
Weather
the short-term, day-to-day condition of the atmosphere
Factors that contribute to weather: (5)
- Temperature
- air pressure
- relative humidity
- wind speed and direction
- seasonal factors
Meteorology
The scientific study of the atmosphere
….. drives the daily drama in the atmosphere as it absorbs and releases vast quantities of heart energy
Water
Airmass
the air that is overlying the surface of earth, and this air takes the moisture and temperature of the surface
moist and dry areas
Continental: DRY
Maritime: moist
Arctic: VERY COLD
Polar: COLD
Tropical: Warm to HOT
Describe the lake effect
when below freezing air passes over a lake and gains warmth, and gets humidified.
What happens to the airmass when it is lifted?
it is cooled down adiabatically (by expansion
What are the 4 types of lifting
1- Convergent lifting
2- convectional lifting
3-orographic lifting
4-Frontal lifting
Convergent lifting:
when air flows toward an area of low pressure. Air from different directions move to the same low pressure area converging, displacing air upwards
ex: the southeast and northeast trade winds converge, forming an intertropical convergence zone (ITCZ) and areas of convergent uplift
Convectional lifting:
Convectional lifting: When an air mass from a maritime source region to a warmer continental region, heating from the warmer land surface causes lifting and convection in the air mass. Unstable conditions cause clouds to form as uplifting keeps occurring.
Ex: Urban surfaces with high albedo, and desert hot surface
Orographic lifting:
air is forcibly lifted upslope as it is pushed against a mountain. The lifting air cools adiabatically.
orographic barrier enhances convectional activity
Rain shadow:
The dry side (leeward side)
Leeward side: air descends, heats up, and becomes dry
Chinook winds:
the warm, downslope airflows characteristic of the leeward side of mountains
Windward side of the mountain:
air rises, cools, and precipitates
What is a front?
a boundary where 2 different air masses meet
cold front: cold air mass
warm front: warm air mass
Cold front:
When a dense, cold air mass pushes warm air upward
This lifting of warm air causes it to cool then form clouds
Warm front:
warm air mass moves into a colder region but can’t push the dense cold air out of the way so Instead, the warm air slides over the cold air, forming a wedge shape
Also forms clouds as the warm air rises gently
the temperature inversion it sometimes causes can lead to stagnant air
Midlatitude cyclonic systems:
Vast low-pressure system that migrates across a continent pulling air masses into conflicts along fronts
moves from west to east
Ground based doppler radar:
used to locate precipitation
Calculate its motion
estimate its type
Satellites and radar stations
different forms of weather forcasting
Thunderstorms:
warm, moist surface air
A conditionally unstable atmosphere
Convection lifting
cumulonimbus clouds
heavy rain and hail
gusty winds
thunder and lightening
possible tornadoes
Winter storms and blizzards:
- Large systems
- Heavy snowfall
- freezing rain
- High winds
- Snow and ice cripple infrastructure
Damaging winds:
Straight-line winds or derecho-severe, fast moving thunderstorms
- downbursts – thunderstorms
- microbursts – affects less that 4 km^2
- plough winds: effect and damages crops
Tornadoes:
Associated with thunderstorm squall lines and supercell thunderstorms
Violently rotating column of air in contact with the ground surface
Tropical cyclones (big topic)
1/6:
- originate in the tropics
- sea surface temperatures exceed 26 degrees to a depth of 60m
- homogenous air mass, warm air, highly humid
- heat energy from the ocean gets converted to mechanical energy (wind)
2/6
- Low pressure center
- steep pressure gradients generate inward spiraling winds
- high precipitation at the eye wall
3/6
- classification based on wind speed + meteorological features
- 100s to over 1500 km wide
- full height of the troposphere
4/6
- high damage potential
5/6
- about 80 tropical cyclones occur per year
- 45 are powerful enough to be classified as hurricanes
6/6
- results in economic + insured losses
- Higher economic loss than insured
