Physical geography: exam 2 – Flashcards
Unlock all answers in this set
Unlock answersquestion
Troposphere
answer
Lowest layer Most active zone Majority of nonmarine living organisms Where weather happens Temperature decreases with increasing altitude
question
Tropopause
answer
the upper limit of the Troposphere Higher over the Equator Lower over the poles
question
Mesosphere
answer
Immediately above the Stratopause Coldest of all layers Temperature decreases with increasing altitude
question
Mesopause
answer
the upper limit of the Mesosphere
question
Thermosphere
answer
Uppermost layer Gases are sorted into a variety of sublayers based on molecular mass Temperature increases with increasing altitude Intense solar reactions cause molecules to vibrate at very high speeds creating kinetic energy
question
Intense solar reactions cause..
answer
molecules to vibrate at very high speeds creating kinetic energy
question
Kinetic Energy
answer
the energy of motion of molecules and is measured as temperature
question
Atmospheric Temperature
answer
a measure of kinetic energy within a unit of space in the air
question
Surface Temperature
answer
a measure of kinetic energy contained in a region very close to Earth's surface
question
Three temperature scales
answer
Fahrenheit, Celsius, Kelvin
question
Wind Chill Index
answer
Calculated using: Actual air temperature, wind speed, and heat loss theory Higher wind speed, the lower wind chill
question
Heat Index
answer
Measures apparent temperature using:Actual air temperature and relative humidity Higher humidity, the higher heat index
question
Influences of Air Temperature: Latitude
answer
Differences in the angle of incidence cause energy to be directed in smaller or larger surface areas Results in distinct temperature differences Low latitudes vs. high latitudes
question
Influences of Air Temperature: Seasons and Length of Day
answer
Axial tilt and migration of subsolar point Influences net radiation between hemispheres Influences day length and daily radiation patterns
question
Influences of Air Temperature: Time of day
answer
Sun arc across the sky: Sunrise, solar noon, and sunset Temporal Lag between highest Sun angle and warmest temperature
question
Maritime places are located..
answer
within or near a very large body of water
question
Continental places are surrounded by
answer
landmasses
question
Maritime Effect
answer
Water heats more slowly, storing energy Radiation penetrates to lower depths Heated water mixes with cooler water Evaporation transfers energy to atmosphere
question
Continental Effect
answer
Land heats quickly, not storing any energy Radiation does not penetrate surface No mixing of heated and cooled land Low evaporation rates
question
Temperature increase associated with cities, result of urban surfaces:
answer
Darker surfaces have lower albedo and high sensible heat Less forest cover means more energy is conducted raising temperature Less water on surface and not able to moderate temperature Additional heat is generated from human energy use as electricity for air conditioning and lighting
question
Altitude
answer
Temperature decreases with increased elevation
question
Position of topographic barriers
answer
Topographic barriers, like mountain ranges, influence cooling or warming of air that traverse them
question
Windflow patterns
answer
Direction of windflow can change air temperature depending on source of air, its modification, and barriers
question
Hypothetical Continent
answer
Surrounded by ocean Straddles the Equator Isotherms indicate the combined effect of: Maritime/Continental effects Seasonality
question
Air Pressure
answer
the measured weight of air as it exerts pressure on Earth's surface
question
Air pressure decreases..
answer
with increasing altitude
question
Air density is greatest..
answer
near the Earth's surface
question
Warm air results in..
answer
lower air pressure
question
Cooler air results in..
answer
higher air pressure
question
Measuring Air Pressure
answer
Barometer
question
Mapping Air Pressure
answer
Air pressure changes with altitude
question
High-Pressure System
answer
A circulating body of air that exerts relatively high pressure as air sinks toward the surface Air flow diverges
question
Low-Pressure System
answer
A circulating body of air where relatively less pressure is created as air rises away from the surface Air flow converges
question
Advection
answer
the process by which air flows horizontally from high-pressure to low-pressure
question
Map of Atmospheric Pressure
answer
Isobars indicate the geographic patterns of pressure systems Red arrows illustrate the path of air flow relative to pressure systems
question
Wind direction
answer
Winds are named for the direction they originate (Northerlies, Easterlies, Southerlies, Westerlies)
question
Unequal Heating of Land Surfaces
answer
Variation in the amount of solar radiation received by latitude Air density and pressure differ from place to place Surface air flows from high to low pressure to balance the difference
question
Convection
answer
causes motion in the atmosphere
question
Air flows from..
answer
areas of high pressure to low pressure
question
Pressure gradient
answer
The greater the difference in pressure, the steeper the gradient The steeper the gradient, the faster the air flow
question
The Direction of Air Flow: Coriolis Force
answer
Due to Earth's rotation Deflects objects traveling in the atmosphere Earth's eastward rotation below Northern Hemisphere, deflection is to the right Southern Hemisphere, deflection is to the left
question
Frictional Forces
answer
Occurs at ground level Strongest at surface, diminishing at about 1500 m (5000 ft) Causes wind to slow down and move in irregular ways
question
Convection Loops
answer
spiraling descending and rising air are linked horizontally by advection
question
Global Pressure and Atmospheric Circulation
answer
Simplified system on an Earth that is nonrotating, untilted, and has a uniform surface
question
Hadley Cell
answer
the tropical convection loop Air at tropics is warmed by year-round direct sunlight
question
Intertropical Convergence Zone (ITCZ)
answer
Warming creates a zone of low pressure at Equator as air rises into the atmosphere Winds converge into ITCZ by advection
question
Subtropical High (STH) Pressure System
answer
Air rising from ITCZ eventually sinks at subtropics creating zones of high pressure Dry and warm winds diverge from STH
question
Ferrel Cell
answer
the circulatory loop that mixes cool polar air with warm tropical air
question
Polar Front
answer
the line of contact between contrasting air masses at about 60 degrees N/S
question
Polar Jet Stream
answer
formed by high-altitude winds that are formed with the temperature/pressure gradient
question
Rossby Waves
answer
develop as undulations in the polar front moderate significant temperature difference on either side
question
Polar Cell
answer
the circulatory loop in the polar regions
question
Polar High Pressure System
answer
Air flowing northward from midlatitudes sinks, producing a weak high-pressure system Consists of masses of rotating, descending dry air that flows toward the polar front
question
Trade Winds -->
answer
ITCZ
question
STH -->
answer
Westerlies and Trade Winds
question
Westerlies and Polar Easterlies-->
answer
Polar Front
question
Polar High-->
answer
Polar Easterlies
question
ITCZ migrates..
answer
with subsolar point, as the zone of most intense radiation and warming
question
All large pressure systems migrate..
answer
seasonally due to the consistent distance between them
question
Seasonal shift of the ITCZ and prevailing wind direction in the subtropics
answer
...
question
Asian monsoons: winter
answer
ITCZ in south; cold air, high pressure
question
Asian monsoons: summer
answer
ITCZ in north; warm air, low pressure
question
Sea breeze
answer
Breeze blows from high-pressure sea to low-pressure sea
question
Land breeze
answer
Breeze blows from high-pressure land to low-pressure sea
question
Valley breeze
answer
Breeze blows upslope as mountain slopes heat up
question
Mountain breeze
answer
Breeze blows downslope as mountain slopes cool off
question
Katabatic winds
answer
Extremely cold, dense air flows downslope under force of gravity. Flows at great speeds
question
Chinook winds
answer
Occur when a steep pressure gradient develops in mountainous regions -high pressure on windward side -low pressure on leeward side
question
surface currents are driven by..
answer
winds as energy transfers by friction
question
Gyres form as..
answer
continents block the movement of water
question
Oceanic Conveyor Belt
answer
Slow vertical mix of water between layers of the ocean
question
(OCB) Downwelling currents:
answer
caused by high-density water that is cooler and saltier
question
(OCB) Upwelling currents:
answer
...
question
El Nino and La Nina
answer
Reversal of "normal" flow of currents and winds in tropical pacific Occurs ever 3-8 years Affects climate -Changes ocean surface temperature -Changes patterns of precipitation
question
Adiabatic Processes
answer
Air cools as it rises and expands. Air warms as is sinks and compresses
question
Dry Adiabatic Lapse Rate
answer
Applies to unsaturated air. Dry air cools or warms at 10 degrees C/1000 m. or 5.5 degrees F/1000 ft.
question
Wet Adiabatic Lapse Rate
answer
Applies to air that reaches the lifting condensation level, or the altitude of saturation. Rate varies with moisture content and temperature. Average rate is about 5 degrees C/1000 m. or 2.7 degrees F/1000 ft.
question
Clouds are..
answer
visible masses of suspended, minute water droplets or ice crystals
question
Clouds form in..
answer
regions with high water vapor density
question
Two necessary conditions for cloud formation:
answer
Air must be saturated and must be a substantial quantity of small airborne particles for water vapor to collect on
question
Cloud form
answer
Cirrus, cumulus, and stratus
question
Cloud altitude
answer
High, middle, and low
question
Cirrus clouds
answer
Featherlike; high altitude in the troposphere
question
Stratus clouds
answer
Blanket the sky, overcast; lower part of the atmosphere (fog)
question
Cumulus clouds
answer
Cotton ball appearance; low to mid elevation
question
Cirrocumulus clouds
answer
Pretty high in atmosphere, some amount of puffiness
question
Altocumulus clouds
answer
Mid-level clouds; puffy; blanket the sky
question
Altostratus clouds
answer
Mid-level clouds
question
Cirrostratus clouds
answer
Resemble cirrus, but not quite as featherlike
question
Cumulonimbus
answer
Thunderstorm clouds
question
Stratocumulus
answer
Takes on the appearance of a stratus and cumulus cloud
question
Contrails
answer
created by exhaust from airplanes
question
Fog
answer
(Stratus clouds) Condensing of water vapor close to the ground Burns off when cool air forming fog warms above the dew-point as the day progresses
question
Radiation fog
answer
develops at night when air cools to the dew-point and is held below a temperature inversion, or an overlying body of warmer air
question
Advection fog (Sea fog)
answer
develops when warm air flows over a cooler surface, cooling it to the dew-point
question
Precipitation
answer
Forms within clouds when droplets or ice crystals grow and fall to Earth
question
Rain
answer
unfrozen water droplets
question
Snow
answer
ice crystals
question
Sleet
answer
rain freezes before hitting the ground
question
Freezing rain
answer
rain freezes on impact with the ground
question
Hail
answer
ice crystals that melt and refreeze before falling
question
H2O molecule
answer
combination of 1 oxygen with 2 hydrogens -Positive charge at O -Negative charge at H2
question
Hydrogen Bonding
answer
Attraction between the hydrogen atoms of water molecules; explains water's physical states
question
Water absorbs and releases..
answer
latent heat
question
When water changes physical states, energy is..
answer
either absorbed or released: melting, freezing, evaporation, condensation, sublimation, deposition
question
The Hydrologic Cycle
answer
Movement of water between various storage locations; amount of water is finite; total amount evaporated equals the total precipitated globally
question
Humidity
answer
refers to the concentration of water vapor in the air
question
Maximum humidity
answer
Maximum amount of water vapor that a body of air can hold; warm air can hold more water vapor than cold air
question
Saturation
answer
the point where the air cannot hold any more water vapor at its current temperature
question
Saturation curve
answer
describes the relationship between maximum humidity and temperature
question
Maximum humidity rises with...
answer
temperature
question
Specific humidity
answer
How much water vapor is actually in the air
question
Relative humidity
answer
Ratio of specific humidity to maximum humidity; how close the air is to saturation at its current temperature
question
Lower latitudes
answer
Specific humidity is high Relative humidity is low
question
Higher latitudes
answer
Specific humidity is low Relative humidity is high
question
Diurnal Cycle
answer
Max humidity increases with warming; specific humidity is constant; relative humidity gradually decreases
question
Dew-point temperature
answer
Temperature at which a mass of air is saturated; related to changes in relative or specific humidity: When a body of air cools to point of saturation, it is 100% relative humidity
question
Evaporation
answer
Transformation of liquid water into water vapor
question
Transpiration
answer
results in evaporation directly from leaf pores in plants into the atmosphere
question
All precipitation occurs when...
answer
an air mass rises sufficiently high to condense large quantities of water
question
Four types of lifting:
answer
Convectional uplift, orographic uplift, frontal uplift, convergent uplift
question
Orographic uplift
answer
Airflow interrupted by a mountain range
question
Windward side
answer
Air cools at DALR to dew-point; forms clouds that cool at WALR and precipitation follows
question
Leeward side
answer
Air descends downslope, warming at DALR; creates rain shadow of dry conditions
question
Convectional uplift
answer
Unequal heating of Earth's surfaces
question
Stability of air:
answer
the potential for convection
question
Stable air
answer
little convection and no precipitation
question
Unstable air
answer
strong convection bubbles lift and create precipitation
question
Air mass
answer
a large body of the lower atmosphere with uniform conditions of temperature and moisture
question
Air mass source regions
answer
any large body of land or water where air derives its characteristics
question
Air mass is categorized by..
answer
Moisture content: c = continental (dry), m = maritime (moist) Latitude (temperature): A = Arctic or Antarctic, P = Polar (50-60 degrees N/S)
question
Fronts
answer
Boundaries between differing air masses; when one air mass advances in a front, frontal uplift causes clouds and/or precipitation
question
Warm front
answer
Warm air advances; warm air slowly lifted
question
Cold front
answer
Cold air advances; warm air rapidly lifted
question
Midlatitude Cyclones
answer
A well-organized low-pressure system that migrates across a region while it spins
question
Midlatitude Cyclones: Upper Air Flow
answer
500 mb upper air-pressure surface; occurs at a specific but varying altitude over and given place on Earth; vertically divides atmosphere in two
question
Cyclogenesis
answer
the processes forming midlatitude cyclones
question
Cumulus stage
answer
Begins with convection or advancing cold front into mT air; rapid rising air forms cumulus clouds
question
Developing Stage
answer
Condensation releases latent heat
question
Mature Stage
answer
Very unstable air with development of strong updrafts; intense precipitation brings cold air down to create downdrafts
question
Dissipation Stage
answer
...
question
Production of lightning
answer
Collisions among ice crystals and rain droplets cause difference in electrical charge within clouds
question
(Lightning) Ground has...
answer
positive charge (+)
question
(Lightning) Clouds have...
answer
positive charge (+) at top and negative charge (-) at base
question
In strong storms...
answer
leader (-) from cloud meets streamer (+) from ground, creating "spark" as cloud-to-ground lightning
