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geol module 4, geol module 5, geol module 6, geol module 7

Terms in this set (130)

Air Pressure
The pressure exerted by the weight of air above a given point, usually expressed in millibars (mb) or inches of mercury (in. Hg)
Mercury barometer:
- Column of mercury in a glass tube under vacuum
- Mercury rises or falls with changes in air pressure
Aneroid barometer:
- Small, sealed chamber partially emptied of air
- Chamber connected to a mechanism that is sensitive to changes in the chamber
- As air pressure varies, mechanism moves needle on a dial
Wind is
the horizontal motion of air across Earth's surface
Turbulence refers to
wind updrafts and downdrafts
Driving Forces within the Atmosphere
Gravity
Pressure
Gradient Force
Coriolis Force
Friction Force
Anemometer
measures wind speed
Wind vane
determines the wind direction
A pressure gradient force is created because of
a pressure difference between high- and low-pressure areas
Winds tend to move from _____ to _____ pressure
high, low
isobars
- lines of equal pressure
- The closer together the lines, the stronger the wind
Because the earth is a sphere and rotates on its axis, air moving across the surface appears to ___
curve
In the northern hemisphere, this curvature is to the ___.
right
In the southern hemisphere, this curvature is to the ___.
left
Variables affecting friction:
- Surface texture
- Wind speed
- Time of day and year
- Atmospheric conditions
Primary high- and low-pressure areas are
Interrupted cells or uneven belts of similar pressure that stretch across the globe
Secondary high- and low-pressure areas:
- Smaller than the primary systems:
- Form within the primary pressure areas
- Range from a few hundred to a few thousand kilometers in diameter
- Hundreds to thousands of meters high
Primary High-Pressure and Low Pressure Areas:
-___________ ___ pressure trough
- __________ ___-pressure cells
- _________ ___-pressure cells
- _________ ___-pressure cells
Equatorial low
Subtropical high
Subpolar low
Polar high
In the ________ hemisphere, trade winds blow mainly towards the ________
northern, southwest
Trade winds in the _______ hemisphere are important in affecting ______ ______
southern, El Nino
Rising air within ITCZ, once aloft, moves towards the _______
poles
Westerlies occur at _________ latitudes than the trade winds
higher
In northern hemisphere, westerlies mainly blow from the ____ towards the _______
west, northeast
Polar atmospheric mass is _____ and receives _______ energy from the sun
small, little
An isobaric (pressure) surface for the upper atmosphere undulates:
- Ridges of _____ _________ where winds slow and converge (pile up) in __________ motion
- Troughs of _____ ________ where winds accelerate and diverge in __________ circulation
high pressure, anticyclonic
low pressure, cyclonic
A jet stream is
a region or band of high winds
what are the two major jet streams?
polar and subtropical
The basic cause of the two jet streams is
the rapid change in atmospheric temperature in the middle latitudes (Cold, dense air mass to the north, Warm, moist air mass to the south)
when are jet streams most intense and why?
in the winter because the temperature contract is greatest
Local Winds
- Land-sea breezes
- Mountain-valley breezes
- Katabatic winds
- Monsoonal winds
_____, _____ dense air rises next to ____ _____ air, which sinks
warm, less
cool, denser
Katabatic winds are _______ and occur on a _________ scale than mountain-valley breezes
stronger, larger
Layers of air at the surface of a highland or plateau _____, becomes denser, and flows ____-_____
cools, down-slope
Ocean circulation is driven by contrasts in __________, composition, and ______ of ocean waters
temperature, density
three layers of the ocean
surface water, intermediate water (mixing zone), deep water
The surface ocean layer is in direct contact with the ________ and warmed by the ____ energy
atmosphere, sun's
Ocean currents distribute ____ and ______ in the oceans
heat, nutrients
Ocean currents move in ______ and ________ directions
definite, predictable
The direction of currents is influenced by the ________ Effect
Coriolis
Several system fluctuations occur in multiyear or shorter periods due to ______ in the _____ and/or _____ of primary high and low pressures
changes, strength, location
North Atlantic Oscillation
Pressure differences between the Icelandic low and Azores high alternate in strength
Pacific Decadal Oscillation
Involves temperature and pressure fluctuations between the northern and tropical Pacific Ocean over durations of 20-30 years
Southern Oscillation
Originates in the tropical Pacific and accompanies El Nino
Three Phases of Water
water vapor (gas phase), water (liquid phase), ice (solid phase - less dense than liquid water)
for water phase changes, ____ energy must be ______ or ___________
heat, added, released
sublimation
direct change of water vapor to ice or ice to water vapor
Specific Humidity =
grams of water vapor/Kg of air
Maximum specific humidity ______ with temperature
increases
________ air can hold __________ water vapor
warmer, more
Relative Humidity =
mass of water in air x 100/mass of water air can hold
Dew Point
Temperature at Which Water Vapor Begins to Condense
Vapor Pressure
The Amount of Pressure Exerted By Water Vapor in the Atmosphere
As more water vapor enters the atmosphere, the amount of pressure exerted by that water vapor ________. When the vapor pressure ________ is reached, no more water can enter the atmosphere and the atmosphere is _________.
increases, maximum, saturated
The ______ the temperature, the ________ the saturation vapor pressure
higher, greater
Two opposing forces work on a parcel of air:
- Upward ________ force
- Downward ________ force
buoyancy, gravitational
The warming and cooling rates for a parcel of expanding or compressing air are termed _____________:
- Ascending air parcel ________ by expansion in response to reduced pressure at higher altitudes
- Descending air _______ by compression due to increasing pressure at lower altitudes
adiabatic, cools, heats
_____ adiabatic rate is the rate at which "dry" air cools by expansion or ______ by compression
dry, heats
______ adiabatic rate (MAR) is the average rate at which ascending air that is moist (saturated) ______ by expansion
moist, cools
Dry adiabatic rate
- 10 C/1000 m
- 5.5 F/1000 ft
Moist adiabatic rate
- 6 C/1000 m
- 3.3 F/1000 ft
________ lapse rate: Average ______ in temperature with _______ altitude (6.4 Co per 1000 m) for still, calm air
normal, drop, increasing
___________ lapse rate: Actual lapse rate for air at a particular place and time:
- Can be lower or higher than the normal lapse rate depending on conditions
environmental (stable atmospheric conditions=less than DAR and MAR)
- Rising air parcel cools to _____ ______
- Further lifting causes active _______________ of water vapor around condensation nuclei (dust, soot, ash, etc.)
- _______ initially composed of microscopic moisture droplets
- A million or more moisture droplets aggregate to form a rain drop
dew point, condensation, cloud
stratiform
Develop horizontally as flat and layered clouds (low to middle altitude)
cumuliform
Puffy and globular clouds (low altitude, associated with fair weather)
cirroform
Wispy clouds, usually quite high in altitude and made of ice crystals
Fog
a cloud layer on the ground that restricts visibility to less than 1 km
types of fog:
- Advection fog
- Evaporation fog
- Upslope fog
- Valley fog
- Radiation fog
- ________ fog forms when air in one place migrates to another place where conditions cause saturation
- Warm, _______ air moves over cooler ocean currents, lake surfaces or snow masses
- Air layer directly above the cooler surface is chilled to the ___ ______
advection, moist, dew point
- __________ fog forms when water molecules evaporate from the water surface into cold, overlying _____
- Also known as steam fog or sea smoke
evaporation, air
- (_______ fog) A type of advection fog where moist air is forced to higher elevations along a hill or mountain
- Adiabatic _________ results in cooling and condensation
- Resulting upslope fog forms a stratus cloud at the level of saturation
- Common in winter and spring along the Appalachians and eastern slopes of the Rockies
Upslope, expansion
- _______ fog forms when radiative _______ of a surface chills the air layer directly above the ground to the dew-point temperature
- Often occurs on clear nights over moist ground
radiation, cooling
- Cool, dense air settles in _____-lying areas
- ______ fog forms as a chilled, saturated layer near the ground
low, valley
Air masses are generally classified according to the _______ and ______ characteristics of their source regions
temperature, moisture
Air masses eventually ______ their initial characteristics due to _______ into areas of different moisture and temperature characteristics
lose, migration
Convergent Lifting:
Air flows toward an area of low pressure
Convectional Lifting:
Air lifting stimulated by local surface heating
Orographic Lifting:
Air is forced over a barrier such as a mountain range
Frontal Lifting:
Air lifted along the leading edges of contrasting air masses
occluded front
Faster moving cold front overtakes a warm front
(- Two bodies of cold air associated with each front collide.
- This forces the warm air between them to rise.
- Results in uplift of warm air that is no longer in contact with ground.
- This uplift of warm air results in cloud formation even though frontal system has no contact with the ground.)
Life Cycle of a Midlatitude Cyclone
- Cyclogenesis
- Open stage
- Occluded stage
- Dissolving stage
Storm tracks shift in latitude with the seasons:
- ________ shift in _____ occurs when cP and mT air masses are in greatest conflict
- ___________ frontal activity thus occurs in spring and often associated with thunderstorms and tornadoes
northward, spring, strongest
_____________ may develop within an air mass, along a cold front, or result from orographic lifting along a mountain slope
thunderstorms
How Lightening Possibly Forms:
Precipitation formation and _________ within ______ cloud causes positive and negative charges to develop on different-sized water droplets and/or ice crystals
turbulence, cumulonimbus
- ________ are strong linear winds in excess of 26 m/s (58 mph) associated with thunderstorms and bands of showers
- Capable of overturning boats, hurling flying objects, and breaking tree limbs
- Form when strong _________ in a thunderstorm system blast strong winds _____:
- Linear paths fan out along curved-wind fronts over a wide area of land
Derechos, downbursts, outward
- Begins with a layer of unstable warm, moist air trapped ________ a ceiling of cold, dense air
- Warm buoyant air suddenly finds an _______ in the overlying ceiling
- Warm air rushes rapidly and violently upward through the opening to create a narrow zone of very intense ____ ________
- Surrounding air and associated debris near ground level rushes in from all directions, creating a _____
beneath, opening, low pressure, vortex
Cyclonic motion begins with slowmoving _________ wave of _____ pressure in the trade wind belt and sea-surface temperatures greater than 26 C (79 F):
- Cyclone forms on eastern side of migrating trough of low pressure
easterly, low
Cross-Section of a Hurricane
• ______________ rotation in Northern Hemisphere
• Strong winds spiral _____ in eye wall
• Lowest pressure within ___ where sinking air produces calm conditions
counterclockwise, upward, eye
The Hydrologic Cycle
- Evaporation
- Precipitation
- Ground infiltration
- Surface runoff
- Transpiration
__% of all precipitation on Earth falls over land:
- Over ___ is returned to the atmosphere via _____________
- The remainder flows to the sea as runoff
22, half, evapotranspiration
Evapotranspiration is the combination of ___________ and ____________
evaporation, transpiration
Evaporation:
Net movement of water molecules away from a wet surface into air that is less saturated
Transpiration in plants:
Outward movement of water through small openings (stomata) in the underside of leaves
Precipitation over land that is ___ returned to the atmosphere via evapotranspiration flows back to the sea as _______
Runoff accounts for _% of the entire hydrologic cycle
Runoff follows two basic pathways to the sea:
- Overland flow (95%)
- Subsurface flow as groundwater (5%)
not, 8, runoff
______ can also be measured with a ______, which employs a buried tank opened at the surface
POTET, lysimeter
Hygroscopic water
thin molecular layer of water tightly bound to soil particles but not available for moisture demands
_____________ water is excess water that percolates downward from the _____ capillary zone to the _____ groundwater zone
Gravitational, shallower, deeper
______ water is held in soil by _________ _________ and _______ __________ and is generally accessible to plant roots:
- Field capacity is the ________ amount of water that that can be retained in pore spaces for plants
capillary, surface tension, hydrogen bonding, maximum
Meteorological drought: ______ precipitation, ______ temperatures and ________ in soil moisture
lower, higher, reduction
_________ drought: Changes in soil _______ and weather as they affect crop yields
agricultural, moisture
Hydrologic drought: Reservoir levels ____, stream flow ______ and groundwater mining ______
drop, decreases, increases
Socioeconomic drought:
Water rationing, wildfires, and other problems affecting the economy and society
_________ is water found in the pores of soil and sediment, plus narrow fractures in bedrock
Groundwater is the largest reservoir of fresh water that is readily available to humans:
- About __% of U.S. population derives a portion of its freshwater from groundwater sources
- Groundwater supplies up to ___% of freshwater in some rural areas
groundwater, 50, 100
________ is the percentage of _____ spaces within a given volume of regolith or rock
porosity, open
_________ is a measure of how easily a rock allows fluids to pass through it
Sandstones are typically _____ permeable than clays
Permeability, more
Recharge of groundwater occurs in areas where precipitation seeps downward to the _______ zone:
- In areas of _________ rainfall, the recharge area may encompass the entire landscape beyond stream channels
- In arid regions, recharge occurs _______ an influent stream
- Groundwater then flows to discharge areas
saturation, abundant, beneath
The time water takes to move through the ground from recharge to discharge depends on:
- Permeability of material
- Travel distance
- Path of flow
Artesian system occurs where groundwater under pressure rises above the level of an ______
Two conditions are necessary:
- Aquifer is ______ with one end receiving water (recharge area)
- Aquifer is ______ with aquicludes above and below
aquifer, inclined, confined
In artesian _____, water rises on its own without pumping
Two types of artesian wells:
- ________ occurs when pressure surface is below ground and water does not reach surface
- Pressure surface above ground creates a _______ artesian well
wells, nonflowing, flowing
- In regions where ______ of water exceeds ______, the water table will gradually ______
- If the water table is allowed to drop significantly, land ______ will result
withdrawal, recharge, drop, subsidence
Groundwater can be ________ by:
- Drainage from septic tanks, broken sewers and barnyards
- Agricultural poisons
- Highway _____
- Buried hazardous wastes
- Invading seawater along coastal areas
contaminated, salts
- Water supply in the United States comes from surface and groundwater sources
- In some areas like New England, water supply far ______ usage
- In other areas like the western U.S., water _______ result
exceeds, shortages
- ___________ of seawater can augment diminishing groundwater supplies
- Drinking water is produced from ______ through a series of filters - Desalination usage important today in Australia, Middle East, coastal southern California and Florida
- Volume of fresh water produced by desalination worldwide expected to _____ between 2010-2020
Desalination, seawater, double
- Climate is _____ over time
- Climatic regions are areas with ______ weather statistics
- Climatology is the study of climate
weather, similar
Tropical Rain Forest
- Influenced all year by ITCZ
- Climate is constantly moist and _____
- _____ all year
- Convectional thunderstorms triggered by local heating and trade wind convergence
warm, rainy
Tropical Monsoon Climates
- Principally along ___ areas
- ______ from 6-12 months of the year brought by the ITCZ
- ___ season dominated by subtropical highs that last one or more months
coastal, rainfall, dry
Tropical _____ Climates
- ITCZ dominates during ______ and characterized by _____ conditions
- Dry conditions occur when ITCZ shifts ____ and high pressure dominates
Savanna, summers, wetter, away
Humid ______ Climate
- Hot summers, ____ winters
- Maritime tropical air masses produce convectional showers over land during summer
- Frontal activity with polar air masses in winter produce _____ storm tracks
Subtropical, mild, cyclonic
_____ ______ Coast Climate
- Warm to cool summers, mild winters
- Affected throughout the year by cyclonic systems formed along _____ front
marine west, polar
_________ Climate
- Dry summers brought on by subtropical highs
- Mild winters controlled by cyclonic storm tracts:
- Most precipitation occurs during ______
Mediterranean, winter
Humid ________ Climate
- Hot to warm summers, ____ winters
- Maritime tropical air masses influence both humid continental moist-all-year and winter-dry climates
- In North America, conflict between maritime tropical and continental polar in winter
Continental, cold
_______ Climate
- Cool summers and ____ cold winters
- Dominated throughout the year by continental ___ masses
Subarctic, very, air
Polar ____
- Occur at ____ latitudes and ____ elevations
- Permafrost and ground ice conditions common
- Land under continuous snow cover 8-10 months
- Small plants during spring and short summer
- Never warms above __C
Tundra , high, high, 10
___ deserts:
- Dominated by subtropical ____ pressure
- Tropical and subtropical regions hot
- ___-latitudes are cold
arid, high, mid
____arid steppes (flat grassland):
- Tropical, subtropical hot dominated by high pressure
- Mid-latitude cold occurs poleward of ___ latitude and dominated by continental air mass
semi, 30
_______ _______ by satellites such as Jason-1 and Jason-2 track changing sealevel using radar altimetry
- Data indicate there was a rise in global MSL of 4.5 cm (1.7 inches) from 1993 - 2008.
Rise attributed to two factors:
- ________ ___________ of seawater due to higher temperatures
- _______ of glacial ice and ice sheets
- Scientists estimate that sea-level will rise 1.0 - 1.4 m by the end of this century
remote sensing, Thermal expansion, melting
_____ _______ (CO2 ), _______ (CH4 ) and _____ ______ are essential warmers of the planet:
- Without them the Earth would be an ice ball, 35C colder
Can burning of fossil fuels upset the balance and cause the Earth to warm too much?
Temperatures have increased over the last 50 years! - BUT is the temperature increase related to the increase in CO2?
carbon dioxide, methane, water vapor
The ________ Effect
1. _______ _______ enters atmosphere
2. Some of this energy _____ Earth's surface
3. Surface heat is then ______ outward at longer wavelengths (infrared)
4. Greenhouse gases in atmosphere absorb and re-emit some of this long wavelength energy, trapping heat in the lower atmosphere
Greenhouse, Shortwave radiation, heats, reradiated
Radiative Forcing
- describes the amount by which some perturbation causes Earth's energy balance to deviate from zero
- Positive indicates ______; negative indicates ______
- Greenhouse gases are the _____ contributors to anthropogenic forcing
warming, cooling, largest
Scientists developed a complex computer climate model known as a General ________ Model (GCM)
GCM contains several sub-model programs for:
- Atmosphere
- ________
- Land surface
- __________
- Biosphere
GCMs calculate scenarios of future climate change based on input parameters and variables
Circulation, Ocean, cryosphere
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